An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

An object with a mass too small to sustain the → proton-proton chain and thus become a true star. See → brown dwarf.

→ substellar; → object.

The point on the Earth, or other body, at which a particular star is directly overhead at a given time.

→ substellar; → point.

The fact or condition, for an object, of not being capable to sustain the → hydrogen fusion because of its low mass (less than 0.08 → solar masses).

→ substellar + → -ity.

A coherent component of a larger system.

→ sub-; → system

To be opposite and delimit the extent of an angle or side of a geometric figure.

From L. subtendere "to stretch beneath," from → sub- + tendere "to stretch," cognate with Pers. târ "string," tanidan "to weave," as below.

Zirtânidan from zir-, → sub-, + tânidan from tân "thread, warp of a web," tâl "thread" (Borujerdi dialect), târ "thread, warp, string," related to tur "net, fishing net, snare," from tanidan, tan- "to spin, twist, weave;" Mid.Pers. tanitan; Av. tan- "to stretch, extend;" cf. Skt. tan- to stretch, extend;" tanoti "stretches," tántra- "warp; essence, main point;" Gk. teinein "to stretch, pull tight;" L. tendere "to stretch, as above; Lith. tiñklas "net, fishing net, snare," Latv. tikls "net;" PIE base *ten- "to stretch."

An angle whose two sides pass through the endpoints of an arc.

Subtended p.p. of → subtend; → angle.

The point on the surface of a celestial body where the star is perceived to be directly overhead (in zenith). The sublunar point and subsolar point are the equivalent points for the Moon and Sun, respectively.

→ sub-; → terrestrial.

Fine or delicate in meaning or intent.

M.E. sotil, from O.Fr. sotil, soutil, subtil "adept, adroit; cunning, wise; detailed," from L. subtilis "fine, thin, delicate, finely woven," from → sub- "under" + -tilis, from tela "web, net, warp of a fabric," → texture.

Naqz "subtle, elegant, beautiful, excellent, good."

To take one number away from another; deduct. To perform the arithmetic operation of → subtraction.

From L. subtractus, p.p. of subtrahere "to draw from beneath, take away, draw off," from → sub- "from under" + trahere "to pull, draw."

Zirkaršidan, literally "to draw beneath," from zir-, → sub-, + karšidan "to draw, pul, drag," variant of kašidan "to draw, protract, trail, drag, carry;" Av. karš- "to draw; to plow," karša- "furrow;" Proto-Iranian *kerš-/*xrah- "to draw, plow;" cf. Skt. kars-, kársati "to pull, drag, plow;" Gk. pelo, pelomai "to move, to bustle;" PIE base k^wels- "to plow."
Kâhidan, → decrease.

The operation of finding the difference between two numbers or quantities.

Verbal noun of → subtract.

1) Constituting or involving → subtraction.
2) Math.: Indicating or requiring subtraction; having a → minus sign.

→ subtract; → -ive.

Color produced by mixing pigments rather than light. Mixing all of the subtractive colors together results in the color black. See also → additive color.

→ subtractive; → color.

A special type being part of a more general type, e.g. subtype 2 among G type stars. → subclass.

→ sub-; → type.

1) To happen or terminate according to desire; turn out successfully; have the desired result.
2) To accomplish what is attempted or intended (Dictionary.com).

M.E. succeden, from O.Fr. succeder "to follow on" and directly from L. succedere "come after, follow after; go near to; come under; take the place of," also "go from under, mount up, ascend," hence "get on well, prosper, be victorious," from → sub- "next to, after" + cedere "to go, move" → process.

Kâmyâbidan, back formation from kâmyâbi, → success.

1) The favorable or prosperous termination of attempts or endeavors; the accomplishment of one's goals.
2) A performance or achievement that is marked by success, as by the attainment of honors (Dictionary.com).

From L. successus "an advance, a coming up; a good result, happy outcome," noun use of p.p. of succedere "come after," from suc-, → sub-, + ceder "to go, move," → process.

Kâmyâbi, literally "acquiring, obtaining, finding one's desire, wish," from kâm "desire, wish," → despite, + yâbi, from yâftan "to obtain, find," → interpolation.

1) Achieving or having achieved success.
2) Resulting in or attended with success.

→ success + -ful a suffix meaning "full of, characterized by."

Following in order or in uninterrupted sequence; e.g. → method of successive approximations.

M.E. from M.L. successivus, from successus, p.p. of succedere "come after, go near to," from → sub- "next to, after" + cedere "to go, move."

Peyâpey "successive," from pey "after; step," related to pâ "foot" (Mid.Pers. pâd, pây, Av. pad-, Skt. pat, Gk. pos, gen. podos, L. pes, gen. pedis, P.Gmc. *fot, E. foot, Ger. Fuss, Fr. pied; PIE *pod-/*ped-) + -â- epenthetic vowel + pey, as explained.

The table sugar with chemical formula C₁₂H₂₂O₁₁, which is a particular type of → sugar compounds.

From → sugar + -ose a suffix borrowed from L. denoting "full of, given to."

1) The state or fact of being sufficient.
2) A sufficient number or amount.

→ sufficient + -cy a suffix used to form abstract nouns.

1) Adequate for the purpose; enough.
2) Logic, Math.: A condition which, if true, guarantees that a result is also true. However, the result may also be true if the condition is not met. → if and only if.

M.E., from O.Fr. sufficient, from L. sufficiens, pr.p. of sufficere "supply, suffice," from sub "up to," → sub-, + root of facere "to make," → fact.

Basandé "sufficient, complete, worthy," from *basidan, from bas "many, much," → multi-.