An Etymological Dictionary of Astronomy and Astrophysics

A kind of → deductive reasoning whereby from two initial → propositions (two → premises) a third related proposition (→ conclusion) is derived. The typical form of a → categorical syllogism is “A is B;” “C is A;” “Therefore, C is B.” For example,
“All humans are mortal.” “John is human.”
“Therefore, John is mortal.”

“Mortal” (B) is called the → major term; it occurs in the first premise and is the → predicate of the conclusion. “John” (C), the subject of the conclusion, is called the → minor term. “Human,” which is common to both premises and is excluded from the conclusion, is called the → middle term. See also → Aristotelian forms. Syllogism is purely formal. It does not enrich knowledge, but gives a new presentation to what is already known. It is also possible to have a logically valid syllogism based on → absurd premises. For example, “All cats are mammals.” “All cats are animals.” “Therefore, all animals are mammals.” Syllogism, representing the earliest branch of → formal logic, was developed in its original form by Aristotle in his Organon (Prior Analytics) about 350 BC.
See also:

→ bivalent logic, → polyvalent logic, → symbolic logic, → propositional logic, → first-order logic, → predicate logic, → syllogistic; → fuzzy logic.

Etymology (EN): M.E. silogisme, from O.Fr. silogisme, from L. syllogismus, from Gk. syllogismos “a syllogism,” originally “inference, conclusion; computation, calculation,” from syllogizesthai “bring together before the mind, compute, conclude,” from assimilated form of → syn- “together” + logizesthai “to reason, to count,” from logos “a reckoning, reason,” → logic.

Etymology (PE): Bâhamšomârik, literally “reckoning together,” from bâham “together,” from bâ “with,” → hypo-, + ham,
→ syn-, + šomâr present stem of šomârdan “to reckon, calculate, enumerate, account for,” → count, + suffix -i.

A kind of → deductive reasoning whereby from two initial → propositions (two → premises) a third related proposition (→ conclusion) is derived. The typical form of a → categorical syllogism is “A is B;” “C is A;” “Therefore, C is B.” For example,
“All humans are mortal.” “John is human.”
“Therefore, John is mortal.”

“Mortal” (B) is called the → major term; it occurs in the first premise and is the → predicate of the conclusion. “John” (C), the subject of the conclusion, is called the → minor term. “Human,” which is common to both premises and is excluded from the conclusion, is called the → middle term. See also → Aristotelian forms. Syllogism is purely formal. It does not enrich knowledge, but gives a new presentation to what is already known. It is also possible to have a logically valid syllogism based on → absurd premises. For example, “All cats are mammals.” “All cats are animals.” “Therefore, all animals are mammals.” Syllogism, representing the earliest branch of → formal logic, was developed in its original form by Aristotle in his Organon (Prior Analytics) about 350 BC.
See also:

→ bivalent logic, → polyvalent logic, → symbolic logic, → propositional logic, → first-order logic, → predicate logic, → syllogistic; → fuzzy logic.

Etymology (EN): M.E. silogisme, from O.Fr. silogisme, from L. syllogismus, from Gk. syllogismos “a syllogism,” originally “inference, conclusion; computation, calculation,” from syllogizesthai “bring together before the mind, compute, conclude,” from assimilated form of → syn- “together” + logizesthai “to reason, to count,” from logos “a reckoning, reason,” → logic.

Etymology (PE): Bâhamšomârik, literally “reckoning together,” from bâham “together,” from bâ “with,” → hypo-, + ham,
→ syn-, + šomâr present stem of šomârdan “to reckon, calculate, enumerate, account for,” → count, + suffix -i.

1a) Of or pertaining to a → syllogism.

1b) Like or consisting of syllogisms.

2a) The part of logic that deals with syllogisms.

2b) Syllogistic reasoning (Dictionary.com).

See also: → syllogism; → -ic.

1a) Of or pertaining to a → syllogism.

1b) Like or consisting of syllogisms.

2a) The part of logic that deals with syllogisms.

2b) Syllogistic reasoning (Dictionary.com).

See also: → syllogism; → -ic.

Of or pertaining yo symbiosis in biology, denoting a close, prolonged association between two or more different organisms of different species that may be, but does not necessarily, of mutual benefit. → symbiotic star.

Etymology (EN): From Mod.L., from Gk. symbiosis “a living together,” from symbioun “live together,” from symbios “(one) living together (with another), partner,” from → syn- “together” + bios “life,”
→ bio-.

Etymology (PE): Hamzi “living together,” from ham- “together,” → syn-,

• zi- present stem of zistan “to live,” → bio-.

Of or pertaining yo symbiosis in biology, denoting a close, prolonged association between two or more different organisms of different species that may be, but does not necessarily, of mutual benefit. → symbiotic star.

Etymology (EN): From Mod.L., from Gk. symbiosis “a living together,” from symbioun “live together,” from symbios “(one) living together (with another), partner,” from → syn- “together” + bios “life,”
→ bio-.

Etymology (PE): Hamzi “living together,” from ham- “together,” → syn-,

• zi- present stem of zistan “to live,” → bio-.

A → B[e] star whose spectrum shows the presence of a cool component characterized mainly by → TiO bands.

See also: → symbiotic; → B[e] star.

A → B[e] star whose spectrum shows the presence of a cool component characterized mainly by → TiO bands.

See also: → symbiotic; → B[e] star.

A stellar object whose optical spectrum displays lines characteristic of gases of two very different temperatures, typically of an M star (3500 K) and a B star (20 000 K) superimposed. A symbiotic star is in fact a close binary system.

See also: → symbiotic; → star.

A stellar object whose optical spectrum displays lines characteristic of gases of two very different temperatures, typically of an M star (3500 K) and a B star (20 000 K) superimposed. A symbiotic star is in fact a close binary system.

See also: → symbiotic; → star.

1. Something that stands for or represents something else, especially an object representing an abstraction.
   
2. A conventional sign or character that represents something in a specific context, e.g. an operation or quantity in mathematics or music.

Etymology (EN): M.E., from L.L. symbolum “creed, token, mark,” from Gk. symbolon “sign, mark,” from → syn- “together” + stem of ballein “to throw.”

Etymology (PE): Namâd variant of namud, nemud past stem of nemudan “to show;” Mid.Pers. nimūdan, nimây- “to show,” from O.Pers./Av. ni- “down; into,” → ni- (PIE), + māy- “to measure;” cf. Skt. mati “measures,” matra- “measure;”
Gk. metron “measure;” L. metrum; PIE base *me- “to measure.”

1. Something that stands for or represents something else, especially an object representing an abstraction.
   
2. A conventional sign or character that represents something in a specific context, e.g. an operation or quantity in mathematics or music.

Etymology (EN): M.E., from L.L. symbolum “creed, token, mark,” from Gk. symbolon “sign, mark,” from → syn- “together” + stem of ballein “to throw.”

Etymology (PE): Namâd variant of namud, nemud past stem of nemudan “to show;” Mid.Pers. nimūdan, nimây- “to show,” from O.Pers./Av. ni- “down; into,” → ni- (PIE), + māy- “to measure;” cf. Skt. mati “measures,” matra- “measure;”
Gk. metron “measure;” L. metrum; PIE base *me- “to measure.”

Of or relating to a symbol or symbols; serving as a symbol.

See also: → symbol; → -ic.

Of or relating to a symbol or symbols; serving as a symbol.

See also: → symbol; → -ic.

A modern development of → formal logic based on a system of → symbols and → axiomatics
in accordance with precise rules. It uses a formalized → artificial language to avoid the ambiguities and logical inadequacies of → natural languages. Symbolic logics are → polyvalent when they admit → truth values other than → true and → false.

See also: → symbolic; → logic.

A modern development of → formal logic based on a system of → symbols and → axiomatics
in accordance with precise rules. It uses a formalized → artificial language to avoid the ambiguities and logical inadequacies of → natural languages. Symbolic logics are → polyvalent when they admit → truth values other than → true and → false.

See also: → symbolic; → logic.

A relation between two quantities such that the first is to the second as the second is to the first. In symbols: a R b = b R a. For example, multiplication is an operation with a symmetric relation between the factors: 5 x 3 = 3 x 5.

See also: → symmetric; → relation.

A relation between two quantities such that the first is to the second as the second is to the first. In symbols: a R b = b R a. For example, multiplication is an operation with a symmetric relation between the factors: 5 x 3 = 3 x 5.

See also: → symmetric; → relation.

A tensor that is → invariant under any → permutation of its indices (→ index). In other words, a tensor that equals its → transpose. For example, a second-order → covariant tensor A_jk if its components satisfy the equality: A_jk = A_kj.

See also: → symmetric; → tensor.

A tensor that is → invariant under any → permutation of its indices (→ index). In other words, a tensor that equals its → transpose. For example, a second-order → covariant tensor A_jk if its components satisfy the equality: A_jk = A_kj.

See also: → symmetric; → tensor.

Characterized by or exhibiting → symmetry.

See also: Adj. of → symmetry.

Characterized by or exhibiting → symmetry.

See also: Adj. of → symmetry.

1. A quality of a geometric figure that has exactly similar parts with respect to a point, a line, or a plane of its own.
   

2. A geometric transformation that does not alter neither the shape nor the size of a figure.
   

3. A property of a mathematical function whose value does not change when its variables are interchanged.
   

4. Of physical phenomena, the property of remaining invariant under certain changes (as of rotation, reflection, inversion in space, the sign of the electric charge, parity, or the direction of time flow). See also → Noether’s theorem.
   

See also:
→ asymmetry, → axial symmetry, → axisymmetry, → baryon asymmetry, → charge-parity symmetry, → dissymmetry, → gauge symmetry, → parity symmetry, → spherical symmetry, → spontaneous symmetry breaking, → supersymmetry, → symmetry group, → T-symmetry.

Etymology (EN): From L. symmetria, from Gk. symmetria “agreement in dimensions, due proportion, arrangement,” from symmetros “having a common measure, even, proportionate,” from → syn- “together”

• metron “meter;” PIE base *me- “to measure;” cf. O.Pers., Av. mā- “to measure;” Skt. mati “measures;” L. metri “to measure.”

Etymology (PE): Hamâmun from ham-, → syn- “together,” + -â- epenthetic vowel + mun, variant mân “measure,” as in Pers. terms pirâmun “perimeter,” âzmun “test, trial,”
peymân “measuring, agreement,” peymâné “a measure; a cup, bowl,”
from O.Pers./Av. mā(y)- “to measure;” cf. Skt. mati “measures,” matra- “measure;” Gk. metron “measure;” L. metrum; PIE base *me- “to measure.”

1. A quality of a geometric figure that has exactly similar parts with respect to a point, a line, or a plane of its own.
   

2. A geometric transformation that does not alter neither the shape nor the size of a figure.
   

3. A property of a mathematical function whose value does not change when its variables are interchanged.
   

4. Of physical phenomena, the property of remaining invariant under certain changes (as of rotation, reflection, inversion in space, the sign of the electric charge, parity, or the direction of time flow). See also → Noether’s theorem.
   

See also:
→ asymmetry, → axial symmetry, → axisymmetry, → baryon asymmetry, → charge-parity symmetry, → dissymmetry, → gauge symmetry, → parity symmetry, → spherical symmetry, → spontaneous symmetry breaking, → supersymmetry, → symmetry group, → T-symmetry.

Etymology (EN): From L. symmetria, from Gk. symmetria “agreement in dimensions, due proportion, arrangement,” from symmetros “having a common measure, even, proportionate,” from → syn- “together”

• metron “meter;” PIE base *me- “to measure;” cf. O.Pers., Av. mā- “to measure;” Skt. mati “measures;” L. metri “to measure.”

Etymology (PE): Hamâmun from ham-, → syn- “together,” + -â- epenthetic vowel + mun, variant mân “measure,” as in Pers. terms pirâmun “perimeter,” âzmun “test, trial,”
peymân “measuring, agreement,” peymâné “a measure; a cup, bowl,”
from O.Pers./Av. mā(y)- “to measure;” cf. Skt. mati “measures,” matra- “measure;” Gk. metron “measure;” L. metrum; PIE base *me- “to measure.”

A group of symmetry-preserving operations composed of all rigid motions or similarity transformations of some geometric object onto itself.

See also: → symmetry; → group.

A group of symmetry-preserving operations composed of all rigid motions or similarity transformations of some geometric object onto itself.

See also: → symmetry; → group.

A prefix occurring in loanwords from Gk., having the same function as → co-; used, with the meaning “with, together,” in the formation of compound words. Variants sy-, syl-, sym-, sys-.

Etymology (EN): From Gk. syn “with, together with,” of unknown origin.

Etymology (PE): Ham- “together, with; same, equally, even,” Mid.Pers. ham-, like L. com- and Gk. syn- with neither of which it is cognate. O.Pers./Av. ham-, Skt. sam-; also O.Pers./Av. hama- “one and the same,” Skt. sama-, Gk. homos-;
originally identical with PIE numeral *sam- “one,” from *som-. The Av. ham- appears in various forms: han- (before gutturals, palatals, dentals) and also hem-, hen-.

A prefix occurring in loanwords from Gk., having the same function as → co-; used, with the meaning “with, together,” in the formation of compound words. Variants sy-, syl-, sym-, sys-.

Etymology (EN): From Gk. syn “with, together with,” of unknown origin.

Etymology (PE): Ham- “together, with; same, equally, even,” Mid.Pers. ham-, like L. com- and Gk. syn- with neither of which it is cognate. O.Pers./Av. ham-, Skt. sam-; also O.Pers./Av. hama- “one and the same,” Skt. sama-, Gk. homos-;
originally identical with PIE numeral *sam- “one,” from *som-. The Av. ham- appears in various forms: han- (before gutturals, palatals, dentals) and also hem-, hen-.

A line connecting the dust grains in a comet tail that left the nucleus at the same time. → syndyne.

Etymology (EN): From L. synchronus “simultaneous,” from Gk. synchronos “happening at the same time,” from → syn- “together”

• khronos “time.”

Etymology (PE): Hamzamân, from ham-, → syn- “together” + zamân, → time.

A line connecting the dust grains in a comet tail that left the nucleus at the same time. → syndyne.

Etymology (EN): From L. synchronus “simultaneous,” from Gk. synchronos “happening at the same time,” from → syn- “together”

• khronos “time.”

Etymology (PE): Hamzamân, from ham-, → syn- “together” + zamân, → time.

1. Going on at the same rate and exactly together. Compare → simultaneous.
   

2. Having the same period and phase of oscillation or cyclic movement.

Etymology (EN): From L. synchronus “simultaneous,” from Gk. synchronos “happening at the same time,” from → syn- “together”

• khronos “time.”

Etymology (PE): Hamgâm literally “at the same pace,” from ham-, → syn-, + gâm “step, pace,” Mid.Pers. gâm, O.Pers. gam- “to come; to go,” Av. gam- “to come; to go,” jamaiti “goes,” Mod.Pers. âmadan “to come,” Skt. gamati “goes,” Gk. bainein “to go, walk, step,” L. venire “to come,” Tocharian A käm- “to come,” O.H.G. queman “to come,” E. come; PIE root *gwem- “to go, come.”

1. Going on at the same rate and exactly together. Compare → simultaneous.
   

2. Having the same period and phase of oscillation or cyclic movement.

Etymology (EN): From L. synchronus “simultaneous,” from Gk. synchronos “happening at the same time,” from → syn- “together”

• khronos “time.”

Etymology (PE): Hamgâm literally “at the same pace,” from ham-, → syn-, + gâm “step, pace,” Mid.Pers. gâm, O.Pers. gam- “to come; to go,” Av. gam- “to come; to go,” jamaiti “goes,” Mod.Pers. âmadan “to come,” Skt. gamati “goes,” Gk. bainein “to go, walk, step,” L. venire “to come,” Tocharian A käm- “to come,” O.H.G. queman “to come,” E. come; PIE root *gwem- “to go, come.”

→ synchronous rotation.

See also: → synchronous; → orbit.

→ synchronous rotation.

See also: → synchronous; → orbit.

Of a body orbiting another, where the orbiting body
takes as long to rotate on its axis as it does to make one orbit.
Therefore it always keeps the same hemisphere pointed at the body it is orbiting. Both bodies are tidally locked (→ tidal locking). This phenomenon is a natural consequence of → tidal braking. Synchronous rotation is common throughout the → solar system. It is found among the satellites of → Mars (→ Phobos and → Deimos), → Jupiter (most of Jupiter satellites, including the → Galilean Moons) and → Saturn (e.g. → Iapetus). Similarly, → Pluto and its moon → Charon are locked in mutual synchronous rotation, with both of them keeping the same faces towards each other.

See also: → synchronous; → rotation.

Of a body orbiting another, where the orbiting body
takes as long to rotate on its axis as it does to make one orbit.
Therefore it always keeps the same hemisphere pointed at the body it is orbiting. Both bodies are tidally locked (→ tidal locking). This phenomenon is a natural consequence of → tidal braking. Synchronous rotation is common throughout the → solar system. It is found among the satellites of → Mars (→ Phobos and → Deimos), → Jupiter (most of Jupiter satellites, including the → Galilean Moons) and → Saturn (e.g. → Iapetus). Similarly, → Pluto and its moon → Charon are locked in mutual synchronous rotation, with both of them keeping the same faces towards each other.

See also: → synchronous; → rotation.

A type of → accelerator that accelerates charged subatomic particles (generally protons) in a circular path. Unlike → cyclotrons, in which particles follow a spiral path,
synchrotrons consist of a single ring-shaped tube through which the
particles loop numerous times, guided by precisely synchronized
magnetic fields and accelerated at various points in the loop by
electric field bursts. See also → synchrotron frequency, → synchrotron radiation.

Etymology (EN): From synchro- a combining form representing synchronized or synchronous in compound words, from L. synchronus “simultaneous,” from Gk. synchronos “happening at the same time,” from → syn- “together”

• khronos “time” + → -tron.

Etymology (PE): Sankrotron, from Fr., as above.

A type of → accelerator that accelerates charged subatomic particles (generally protons) in a circular path. Unlike → cyclotrons, in which particles follow a spiral path,
synchrotrons consist of a single ring-shaped tube through which the
particles loop numerous times, guided by precisely synchronized
magnetic fields and accelerated at various points in the loop by
electric field bursts. See also → synchrotron frequency, → synchrotron radiation.

Etymology (EN): From synchro- a combining form representing synchronized or synchronous in compound words, from L. synchronus “simultaneous,” from Gk. synchronos “happening at the same time,” from → syn- “together”

• khronos “time” + → -tron.

Etymology (PE): Sankrotron, from Fr., as above.

The revolution frequency of a → relativistic particle of charge q and mass m in the
→ uniform magnetic field B of a synchrotron. It is expressed by: f_syn = qB/2πγm, where γ is the → Lorentz factor. This frequency is lower than → cyclotron frequency for a → non-relativistic case.

See also: → synchrotron; → frequency.

The revolution frequency of a → relativistic particle of charge q and mass m in the
→ uniform magnetic field B of a synchrotron. It is expressed by: f_syn = qB/2πγm, where γ is the → Lorentz factor. This frequency is lower than → cyclotron frequency for a → non-relativistic case.

See also: → synchrotron; → frequency.

The electromagnetic radiation emitted by high-energy particles that are moving in magnetic fields, as in a synchrotron particle accelerator.
The acceleration of the moving charges causes the particles to emit radiation. Radio galaxies and supernova remnants are intense sources of synchrotron radiation. Characteristics of synchrotron radiation are its high degree of polarization and nonthermal spectrum.

See also: → synchrotron; → radiation.

The electromagnetic radiation emitted by high-energy particles that are moving in magnetic fields, as in a synchrotron particle accelerator.
The acceleration of the moving charges causes the particles to emit radiation. Radio galaxies and supernova remnants are intense sources of synchrotron radiation. Characteristics of synchrotron radiation are its high degree of polarization and nonthermal spectrum.

See also: → synchrotron; → radiation.

Of a comet, a curve of points calculated assuming dust grains are emitted continuously at successive instants with a constant value of the radiation pressure to gravitational attraction;
also called syndyname. → synchrone.

See also: From → syn- + dyne, → dynamics.

Of a comet, a curve of points calculated assuming dust grains are emitted continuously at successive instants with a constant value of the radiation pressure to gravitational attraction;
also called syndyname. → synchrone.

See also: From → syn- + dyne, → dynamics.

The working together or simultaneous action of separate elements or agencies when the result is greater than the sum of the individual effects or capabilities.

Etymology (EN): From Mod.L. synergia, from Gk. synergia “joint work, help,” from synergos “working together,” related to synergein “to work together, help another,” from → syn- “together” + → ergon, → work, → erg.

Etymology (PE): Hamkâru&#382i, from ham- “together,” → syn-,

• kâru&#382, → energy, + -i noun suffix.

The working together or simultaneous action of separate elements or agencies when the result is greater than the sum of the individual effects or capabilities.

Etymology (EN): From Mod.L. synergia, from Gk. synergia “joint work, help,” from synergos “working together,” related to synergein “to work together, help another,” from → syn- “together” + → ergon, → work, → erg.

Etymology (PE): Hamkâru&#382i, from ham- “together,” → syn-,

• kâru&#382, → energy, + -i noun suffix.

A hypothesized rapidly spinning doughnut-shaped mass of vaporized and molten rock formed from the collision of two planet-sized objects. In numerical simulations studying giant impacts of rotating objects, a synestia can form if the total → angular momentum is greater than the → co-rotational limit. Beyond the co-rotational limit, the velocity at the equator of a body would exceed the orbital velocity

(Simon J. Lock nd Sarah T. Stewart, 2017, arXiv:1705.07858v1).

See also: From → syn- “connected; together” + Hestia the goddess of architecture.

A hypothesized rapidly spinning doughnut-shaped mass of vaporized and molten rock formed from the collision of two planet-sized objects. In numerical simulations studying giant impacts of rotating objects, a synestia can form if the total → angular momentum is greater than the → co-rotational limit. Beyond the co-rotational limit, the velocity at the equator of a body would exceed the orbital velocity

(Simon J. Lock nd Sarah T. Stewart, 2017, arXiv:1705.07858v1).

See also: From → syn- “connected; together” + Hestia the goddess of architecture.

Of or pertaining to the → conjunction of two or more heavenly bodies, especially the interval between two successive conjunctions of a planet or the Moon with the Sun.

Etymology (EN): From L.L. synodicus, from Gk. synodikos, from synodos “assembly, meeting,” from → syn- “together”

• hodos “a going, a way.”

Etymology (PE): Hamâgam, literally “coming together,” from
ham-, → syn- “together,” +
-â- epenthetic vowel + gam from
O.Pers. gam- “to come; to go,”
Av. gam- “to come; to go,” jamaiti “goes,”
Mod.Pers. âmadan “to come,”
gâm “step, pace;” cf. Skt. gamati “goes;”
Gk. bainein “to go, walk, step;” L. venire “to come;”
Tocharian A käm- “to come;” O.H.G. queman “to come;” E. come; PIE stem *gwem- “to go, come.”

Of or pertaining to the → conjunction of two or more heavenly bodies, especially the interval between two successive conjunctions of a planet or the Moon with the Sun.

Etymology (EN): From L.L. synodicus, from Gk. synodikos, from synodos “assembly, meeting,” from → syn- “together”

• hodos “a going, a way.”

Etymology (PE): Hamâgam, literally “coming together,” from
ham-, → syn- “together,” +
-â- epenthetic vowel + gam from
O.Pers. gam- “to come; to go,”
Av. gam- “to come; to go,” jamaiti “goes,”
Mod.Pers. âmadan “to come,”
gâm “step, pace;” cf. Skt. gamati “goes;”
Gk. bainein “to go, walk, step;” L. venire “to come;”
Tocharian A käm- “to come;” O.H.G. queman “to come;” E. come; PIE stem *gwem- “to go, come.”

The interval of 29.530 588 days (29d 12h 44m 2.80s), on average, between two successive → new Moons. Same as → lunation.

See also: → synodic; → month.

The interval of 29.530 588 days (29d 12h 44m 2.80s), on average, between two successive → new Moons. Same as → lunation.

See also: → synodic; → month.

For planets, the mean interval of time between two successive → conjunctions with or → oppositions to the Sun. For example, → Mars has a synodic period of 779.9 days from Earth; thus Mars’ oppositions occur once roughly 2.135 years. In comparison, the synodic period of → Venus is 583.9 days. If the sideral periods of the two bodies around the third are denoted T₁ and T₂, their synodic period is given by: 1/T_syn = |1/T₁ - 1/T₂|.

See also: → synodic; → period.

For planets, the mean interval of time between two successive → conjunctions with or → oppositions to the Sun. For example, → Mars has a synodic period of 779.9 days from Earth; thus Mars’ oppositions occur once roughly 2.135 years. In comparison, the synodic period of → Venus is 583.9 days. If the sideral periods of the two bodies around the third are denoted T₁ and T₂, their synodic period is given by: 1/T_syn = |1/T₁ - 1/T₂|.

See also: → synodic; → period.

Grammar: A word having the same or nearly the same meaning as another in the language. Opposite of → antonym.

Etymology (EN): From L. synonymum, from Gk. synonymon “word having the same sense as another,” from synonymos “having the same name as, synonymous,” from → syn- “together, same” + onyma, → name.

Etymology (PE): Hamcem, from ham-, → syn-, + cem, → meaning.

Grammar: A word having the same or nearly the same meaning as another in the language. Opposite of → antonym.

Etymology (EN): From L. synonymum, from Gk. synonymon “word having the same sense as another,” from synonymos “having the same name as, synonymous,” from → syn- “together, same” + onyma, → name.

Etymology (PE): Hamcem, from ham-, → syn-, + cem, → meaning.

A brief and condensed summary giving the major points and a general view of a topic.

Etymology (EN): L.L. synopsis “a synopsis,” from Gk. synopsis “general view,” from a stem of synoran “to see altogether, all at once,” from → syn- “together” + horan “to see, view.”

Etymology (PE): Hanvin, from han- variant of ham-, → syn-

• vin variant bin present stem of didan “to see,” → phenomenon.

A brief and condensed summary giving the major points and a general view of a topic.

Etymology (EN): L.L. synopsis “a synopsis,” from Gk. synopsis “general view,” from a stem of synoran “to see altogether, all at once,” from → syn- “together” + horan “to see, view.”

Etymology (PE): Hanvin, from han- variant of ham-, → syn-

• vin variant bin present stem of didan “to see,” → phenomenon.

In general, pertaining to or affording an overall view.

See also: M.L. synopticus, from Gk. synoptikos, from
synop-, → synopsis, + -tikos.

In general, pertaining to or affording an overall view.

See also: M.L. synopticus, from Gk. synoptikos, from
synop-, → synopsis, + -tikos.

1. Sun: A map that displays positions of certain events (e.g., → sunspots, → faculae, → filaments, etc.) observed during one solar rotation.
   

2. Meteorology: The use of data obtained simultaneously over a wide area for the purpose of presenting a comprehensive and nearly instantaneous picture of the state of the atmosphere.

See also: → synoptic; → map.

1. Sun: A map that displays positions of certain events (e.g., → sunspots, → faculae, → filaments, etc.) observed during one solar rotation.
   

2. Meteorology: The use of data obtained simultaneously over a wide area for the purpose of presenting a comprehensive and nearly instantaneous picture of the state of the atmosphere.

See also: → synoptic; → map.

The study of the grammatical relationships among signs, independently of their meaning (→ semantics. See also → syntax.

See also: → syntax; → -ics.

The study of the grammatical relationships among signs, independently of their meaning (→ semantics. See also → syntax.

See also: → syntax; → -ics.

1. Linguistics: The branch of → semiotics dealing with the ways in which words are arranged to show connections within the sentence.
   

2. Logic: The study of how signs are combined to form constituents regardless of any interpretation or meaning given to them.
   

3. Informatics: The general set of rules and structural patterns governing the order of words and symbols for issuing commands and writing codes in a programming language.

Etymology (EN): From Fr. syntaxe, from L.L. syntaxis, from Gk. syntaxis “a putting together or in order, arrangement,” from syntassein “to put in order,” from → syn- “together” + tassein “to arrange;” PIE base *tāg- “to put in order.”

Etymology (PE): Amrâž, from am-, variant of ham-, → syn-,

• râž from Av. rāz- “to direct, put in line, set,” rasman- “the lines or files of the army,” razan “rule, order;”
  cf. raj, raž, rak, râk, rezg (Lori), radé, râdé “line, rule, row,” rasté, râsté “row, a market with regular ranges of shops;” ris, risé “straight,” râst “right, true; just, upright, straight,” → system.

1. Linguistics: The branch of → semiotics dealing with the ways in which words are arranged to show connections within the sentence.
   

2. Logic: The study of how signs are combined to form constituents regardless of any interpretation or meaning given to them.
   

3. Informatics: The general set of rules and structural patterns governing the order of words and symbols for issuing commands and writing codes in a programming language.

Etymology (EN): From Fr. syntaxe, from L.L. syntaxis, from Gk. syntaxis “a putting together or in order, arrangement,” from syntassein “to put in order,” from → syn- “together” + tassein “to arrange;” PIE base *tāg- “to put in order.”

Etymology (PE): Amrâž, from am-, variant of ham-, → syn-,

• râž from Av. rāz- “to direct, put in line, set,” rasman- “the lines or files of the army,” razan “rule, order;”
  cf. raj, raž, rak, râk, rezg (Lori), radé, râdé “line, rule, row,” rasté, râsté “row, a market with regular ranges of shops;” ris, risé “straight,” râst “right, true; just, upright, straight,” → system.

The combining of the constituent elements of separate materials or abstract entities into a single or unified entity; opposite of → analysis.
→ aperture synthesis; → nucleosynthesis.
Chemistry: The forming or building of a more complex substance or compound from elements or simpler compounds.
Philo.: The combination or reconciliation of opposed notions.

Etymology (EN): From L. synthesis “collection, set,” from Gk. synthesis “composition,” from syntithenai “put together, combine,” from → syn- “together” + tithenai “to put, place,” from PIE base *dhe- “to put, to do,” cf. Pers. dâdan “to give,” as below.

Etymology (PE): Handâyeš, from han-, variant ham- “together,” → syn- + O.Pers./Av. dā- “to give, grant, put,” dadāiti “he gives;” Mid.Pers./Mod.Pers. dâdan “to give, put”
(cf. Skt. dadáti “he gives;” Gk. tithenai “to place, put, set,” didomi “I give;”
L. dare “to give, offer;” Rus. delat’ “to do;” O.H.G. tuon, Ger. tun, O.E. don “to do;” PIE base *dhe- “to put, to do”)

• -y- epenthetic vowel
• -eš verbal noun suffix, → synthesize.

The combining of the constituent elements of separate materials or abstract entities into a single or unified entity; opposite of → analysis.
→ aperture synthesis; → nucleosynthesis.
Chemistry: The forming or building of a more complex substance or compound from elements or simpler compounds.
Philo.: The combination or reconciliation of opposed notions.

Etymology (EN): From L. synthesis “collection, set,” from Gk. synthesis “composition,” from syntithenai “put together, combine,” from → syn- “together” + tithenai “to put, place,” from PIE base *dhe- “to put, to do,” cf. Pers. dâdan “to give,” as below.

Etymology (PE): Handâyeš, from han-, variant ham- “together,” → syn- + O.Pers./Av. dā- “to give, grant, put,” dadāiti “he gives;” Mid.Pers./Mod.Pers. dâdan “to give, put”
(cf. Skt. dadáti “he gives;” Gk. tithenai “to place, put, set,” didomi “I give;”
L. dare “to give, offer;” Rus. delat’ “to do;” O.H.G. tuon, Ger. tun, O.E. don “to do;” PIE base *dhe- “to put, to do”)

• -y- epenthetic vowel
• -eš verbal noun suffix, → synthesize.

To form a material or abstract entity by combining parts or elements; opposite of → analysis.
Chemistry: To combine (constituent elements) into a single or unified entity.

Etymology (EN): From → synthesis + → -ize.

Etymology (PE): Handâyidan, verbal form of handâyeš,
→ synthesis.

To form a material or abstract entity by combining parts or elements; opposite of → analysis.
Chemistry: To combine (constituent elements) into a single or unified entity.

Etymology (EN): From → synthesis + → -ize.

Etymology (PE): Handâyidan, verbal form of handâyeš,
→ synthesis.

A person or thing that synthesizes.

See also: Agent noun from → synthesize.

A person or thing that synthesizes.

See also: Agent noun from → synthesize.

1. Of, pertaining to, proceeding by, or involving synthesis; opposed to analytic.
   
2. Noting or pertaining to compounds formed through a chemical process by human agency, as opposed to those of natural origin.

See also: Adj. from synthesize.

1. Of, pertaining to, proceeding by, or involving synthesis; opposed to analytic.
   
2. Noting or pertaining to compounds formed through a chemical process by human agency, as opposed to those of natural origin.

See also: Adj. from synthesize.

A method of dividing a polynomial in the special case of dividing by a linear factor. Synthetic division allows one to do long division problems much quicker. It is related to the → Ruffini-Horner method.

See also: → synthetic; → division.

A method of dividing a polynomial in the special case of dividing by a linear factor. Synthetic division allows one to do long division problems much quicker. It is related to the → Ruffini-Horner method.

See also: → synthetic; → division.

A language in which the phrase meaning is determined by case endings of individual words and not by the relation between the words. Old English was a highly synthetic language. Compare with → analytic language.

See also: → synthetic; → language.

A language in which the phrase meaning is determined by case endings of individual words and not by the relation between the words. Old English was a highly synthetic language. Compare with → analytic language.

See also: → synthetic; → language.

A dark triangular plateau near the Martian equator, located in the boundary between the northern lowlands and southern highlands of Mars. Syrtis Major is centered near at 8.4°N 69.5°E, extends some 1,500 km north from the planet’s equator, and spans 1,000 from west to east.

See also: From the classical Roman name Syrtis maior “the Gulf of Sidra” on the coast of Cyrenaica (today Libya)

A dark triangular plateau near the Martian equator, located in the boundary between the northern lowlands and southern highlands of Mars. Syrtis Major is centered near at 8.4°N 69.5°E, extends some 1,500 km north from the planet’s equator, and spans 1,000 from west to east.

See also: From the classical Roman name Syrtis maior “the Gulf of Sidra” on the coast of Cyrenaica (today Libya)

1a) An assemblage or combination of things or parts forming a complex or unitary whole.

1b) An ordered and comprehensive assemblage of facts, principles, doctrines, or the like in a particular field of knowledge or thought (Dictionary.com).

2. Physics: An aggregate composed of physical bodies which we isolate, in our mind, from the region external to it in order to analyze physical situations. Everything outside the system which has a direct bearing on its behavior is called the → environment.
   

3. Astro.: An entity composed of a number of astronomical objects associated and acting together according to certain natural laws.
   

4. Computers: A system consisting of components (a combination of the hardware, software, and firmware) which are connected together in order to accomplish a specific function or set of functions.

Etymology (EN): From L.L. systema “an arrangement, a whole consisting of several parts,” from Gk. systema “arrangement, organized whole,” from sy-, variant of syn- “together” + ste- variant stem of histanai “to cause to stand” (from PIE base *sta- “to stand;” cf. Pers. ist, istâdan “to stand;” Mid.Pers. êstâtan;
O.Pers./Av. sta- “to stand, stand still; set;” Av. hištaiti; cf. Skt. sthâ- “to stand;” Gk. histemi “put, place, weigh,” stasis “a standing still;” L. stare “to stand;” Lith. statau “place;” Goth. standan; PIE base *sta- “to stand”) + -ma nominal suffix denoting result of action.

Etymology (PE): Râžmân, from raž, from Av. rāz- “to direct, put in line, set,” rasman- “the lines or files of the army,” razan “rule, order” (variants raj, râž, rak, râk, rezg (Lori), radé, râdé “line, rule, row,” rasté, râsté “row, a market with regular ranges of shops;” ris, risé “straight”), related to râst “right, true; just, upright, straight;” Mid.Pers. râst “true, straight, direct,” rây-, râyênitan “to arrange;” Sogdian rəšt “right;”
O.Pers. rāsta- “straight, true,” rās- “to be right, straight, true;” cf. Skt. raj- “to direct, stretch,” rjuyant- “walking straight;” Gk. orektos “stretched out;” L. regere “to lead straight, guide, rule,” p.p. rectus “right, straight;” PIE base *reg- “move in a straight line,” hence, “to direct, rule;” + -mân verbal noun suffix used with present and past stems, as in zâymân, câymân, sâxtemân, goftemân.

1a) An assemblage or combination of things or parts forming a complex or unitary whole.

1b) An ordered and comprehensive assemblage of facts, principles, doctrines, or the like in a particular field of knowledge or thought (Dictionary.com).

2. Physics: An aggregate composed of physical bodies which we isolate, in our mind, from the region external to it in order to analyze physical situations. Everything outside the system which has a direct bearing on its behavior is called the → environment.
   

3. Astro.: An entity composed of a number of astronomical objects associated and acting together according to certain natural laws.
   

4. Computers: A system consisting of components (a combination of the hardware, software, and firmware) which are connected together in order to accomplish a specific function or set of functions.

Etymology (EN): From L.L. systema “an arrangement, a whole consisting of several parts,” from Gk. systema “arrangement, organized whole,” from sy-, variant of syn- “together” + ste- variant stem of histanai “to cause to stand” (from PIE base *sta- “to stand;” cf. Pers. ist, istâdan “to stand;” Mid.Pers. êstâtan;
O.Pers./Av. sta- “to stand, stand still; set;” Av. hištaiti; cf. Skt. sthâ- “to stand;” Gk. histemi “put, place, weigh,” stasis “a standing still;” L. stare “to stand;” Lith. statau “place;” Goth. standan; PIE base *sta- “to stand”) + -ma nominal suffix denoting result of action.

Etymology (PE): Râžmân, from raž, from Av. rāz- “to direct, put in line, set,” rasman- “the lines or files of the army,” razan “rule, order” (variants raj, râž, rak, râk, rezg (Lori), radé, râdé “line, rule, row,” rasté, râsté “row, a market with regular ranges of shops;” ris, risé “straight”), related to râst “right, true; just, upright, straight;” Mid.Pers. râst “true, straight, direct,” rây-, râyênitan “to arrange;” Sogdian rəšt “right;”
O.Pers. rāsta- “straight, true,” rās- “to be right, straight, true;” cf. Skt. raj- “to direct, stretch,” rjuyant- “walking straight;” Gk. orektos “stretched out;” L. regere “to lead straight, guide, rule,” p.p. rectus “right, straight;” PIE base *reg- “move in a straight line,” hence, “to direct, rule;” + -mân verbal noun suffix used with present and past stems, as in zâymân, câymân, sâxtemân, goftemân.

A person in charge of the configuration and administration of a multi-user computer system inside a network.

See also: → system; → manager.

A person in charge of the configuration and administration of a multi-user computer system inside a network.

See also: → system; → manager.

The noise in a radio telescope, composed of the receiver noise and the sky noise.

See also: → system; → noise.

The noise in a radio telescope, composed of the receiver noise and the sky noise.

See also: → system; → noise.

Having, showing, or involving a system, method, or plan.

Etymology (EN): L.L., from Gk. systematikos; → system; → -ic.

Etymology (PE): Râžmânvâr, râžmânmand, from râžmân,
→ system, + -mand suffix of possession.

Having, showing, or involving a system, method, or plan.

Etymology (EN): L.L., from Gk. systematikos; → system; → -ic.

Etymology (PE): Râžmânvâr, râžmânmand, from râžmân,
→ system, + -mand suffix of possession.

The error that is constant in a series of repetitions of the same experiment or observation. Usually, systematic error is defined as the expected value of the overall error. opposite of → random error.

See also: → systematic; → error.

The error that is constant in a series of repetitions of the same experiment or observation. Usually, systematic error is defined as the expected value of the overall error. opposite of → random error.

See also: → systematic; → error.

Biology: The science that deals with the systematic naming and classification of all kinds of organisms.

See also: From → systematic + → -ics.

Biology: The science that deals with the systematic naming and classification of all kinds of organisms.

See also: From → systematic + → -ics.

Relating to or affecting a system as a whole.

See also: → system; → -ic.

Relating to or affecting a system as a whole.

See also: → system; → -ic.

An interdisciplinary field of science which deals with the nature of complex systems in nature, society, and science, and studies complex parts of reality as systems.

See also: → system; → theory.

An interdisciplinary field of science which deals with the nature of complex systems in nature, society, and science, and studies complex parts of reality as systems.

See also: → system; → theory.

The alignment of three or more celestial bodies in the same gravitational system along a nearly straight line.
Conjunction or opposition of a heavenly body with the Sun.

Etymology (EN): From L.L. syzygia, from Gk. syzygia “yoke, pair, union of two, conjunction,” from syzygein “to yoke together,” from → syn- “together” + zygon “yoke,” cognate with Pers. yuq, jug “yoke,” as below.

Etymology (PE): Yujân from yuj “yoke,” variants yuq, juh (Mid.Pers. jug, ayoxtan “to join, yoke;” Av. yaog- “to yoke, put to; to join, unite;” cf.
Skt. yugam “yoke;” Hittite yugan “yoke;” Gk. zygon “yoke,” as above, zeugnyanai “to join, unite;” L. jungere “to join,”
O.C.S. igo, O.Welsh iou, Lith. jungas O.E. geoc. PIE base *yeug- “to join”) + -ân suffix of place and time.

The alignment of three or more celestial bodies in the same gravitational system along a nearly straight line.
Conjunction or opposition of a heavenly body with the Sun.

Etymology (EN): From L.L. syzygia, from Gk. syzygia “yoke, pair, union of two, conjunction,” from syzygein “to yoke together,” from → syn- “together” + zygon “yoke,” cognate with Pers. yuq, jug “yoke,” as below.

Etymology (PE): Yujân from yuj “yoke,” variants yuq, juh (Mid.Pers. jug, ayoxtan “to join, yoke;” Av. yaog- “to yoke, put to; to join, unite;” cf.
Skt. yugam “yoke;” Hittite yugan “yoke;” Gk. zygon “yoke,” as above, zeugnyanai “to join, unite;” L. jungere “to join,”
O.C.S. igo, O.Welsh iou, Lith. jungas O.E. geoc. PIE base *yeug- “to join”) + -ân suffix of place and time.