A large, usually white bird with a long neck that lives on rivers and lakes (family Anatidae, especially genus Cygnus).
M.E., from O.E. swan; cf. O.S. swan, O.N. svanr, M.Du. swane, Du. zwaan, O.H.G. swan, Ger. Schwan, probably literally "the singing bird," from PIE base *swon-/*swen- "to sing, make sound."
Qu "swan," maybe an onomatopoetic word from the sound of swan's call; cf. Russ. ky-ky "cry of a swan."
Fr.: bande de Swan
One of the three prominent bands in the spectra of comets and carbon stars caused by diatomic carbon (C2).
Named after the Scottish physicist William Swan (1818-1894) who first studied the spectral analysis of radical carbon C2 in 1856; → band.
Fr.: nébuleuse du Cygne
Same as → Omega Nebula.
A great number of things especially in motion. → meteorite swarm.
ME; OE swearm; cf. O.S., M.L.G. swarm, Swed. svärm, M.Du. swerm, O.H.G. swarm, Ger. Schwarm "swarm;" O.N. svarmr "tumult."
Qang in Lârestâni "swarm of bees, flies, or the like," Lori qem (qem zaye) "swarm of bees, ants, and the like."
Fr.: rayon de balayage
The → radius of a → supernova remnant (SNR) when, at the end of the → free expansion phase, the mass of the swept-up → shell equals that of the ejected gas from the → supernova explosion. It is given by RSW = (3Me / 4πρ0)(1/3), where Me is the ejected mass and ρ0 is the initial density of the → interstellar medium.
1) degarbân; 2) degarbânidan
Fr.: 1) interrupteur; 2) interrompre
1a) A shift from one to another.
Switch "slender riding whip, flexible stick," probably from a Flemish or Low German word akin to Hanoverian swutsche, a variant of Low Ger. zwukse "long thin stick, switch."
Degarbân, from degar "other, another" (Mid.Pers. dit, ditikar "the other, the second;" O.Pers. duvitiya- "second," Av. daibitya-, bitya- "second;" Skt. dvitiya- "second," PIE *duitiio- "second") + -bân a suffix denoting "keeper, guard," sometimes forming agent nouns or indicating relation, → host.
The act of changing one thing or position for another.
Verbal noun of → switch (v.).
1) A weapon having various forms but consisting typically of a long,
straight or slightly curved blade, sharp-edged on one or both
sides, with one end pointed and the other fixed in a hilt or
M.E.; O.E. sweord; cognate with Du. zwaard, Ger. Schwert, Sw. svärd.
Šamšir, Mid.Pers. šamšêr / šamšyl, Parthian safsêr; cf. Gk. sampsera denoting a "foreign sword." The E. scimitar derives ultimately from šamšir through M.Fr. cimeterre or directly from It. scimitarra, possibly from an unknown Ottoman Turkish word, borrowed from Pers.
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
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.
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.
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.
Fr.: étoile symbiotique
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.
1) Something that stands for or represents something else,
especially an object representing an abstraction.
M.E., from L.L. symbolum "creed, token, mark," from Gk. symbolon "sign, mark," from → syn- "together" + stem of ballein "to throw."
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.
Fr.: logique symbolique
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.
Fr.: relation symétrique
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.
Fr.: tenseur symétrique
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 Ajk if its components satisfy the equality: Ajk = Akj.
Characterized by or exhibiting → symmetry.
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.
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."
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."
Fr.: groupe de symétrie
A group of symmetry-preserving operations composed of all rigid motions or similarity transformations of some geometric object onto itself.