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

General: To rule over, to exercise authority.
Science: To serve as or constitute a law for, e.g. physical laws governing star formation, the Universe, and so on.
To regulate the speed of (an engine) with a governor.

From O.Fr. governer "to govern," from L. gubernare "to direct, rule, guide," originally "to steer," from Gk. kybernan "to steer or pilot a ship" (the root of cybernetics).

Faršâyidan, from Av. fraxšā(y)- "to establish authority, to deploy lordship," from fra- "forward, forth" (Av. pouruua- "first"; cf. Skt. pūrva- "first," pra- "before, formerly," Gk. pro; L. pro; O.E. fyrst "foremost," superlative of fore, from P.Gmc. *furisto; E. fore) + xšā(y)- "to rule, have power," xšayati "has power, rules," xšāyô "power;" O.Pers. xša- "to rule," pati-xša- "to have lordship over," Xšyāršan- "hero among kings" or "ruling over heroes" the proper name of the Achaemenid emperor Hellenized as Xerxes, upari.xšay- "to rule over," xšāyaθiya- "king;" Mid.Pers. šâh "king," pâdixšâ(y) "ruler; powerful; authoritative;" Mod.Pers. šâh "king," pâdšâh "protecting lord, emperor, monarch, king," šâyestan "to be worth, suit, fit;" cf. Skt. ksā- "to rule, have power," ksáyati "possesses;" Gk. ktaomai "I acquire," ktema "piece of property;" PIE base *tkeh- "to own, obtain."

The way that a city, company, etc., is controlled by the people who run it (Merriam-Webster.com).

→ govern; → -ance.

1) The act or process of governing; specifically: authoritative direction or control.
2) The organization, machinery, or agency through which a political unit exercises authority and performs functions and which is usually classified according to the distribution of power within it.
3) The complex of political institutions, laws, and customs through which the function of governing is carried out (Merriam-Webster.com).

→ govern; → -ment.

A regulating device for maintaining uniform speed regardless of changes of load, as by controlling the supply of gas, steam, fuel, etc.

Agent noun from → govern; → -or.

A block of the Earth's crust, bounded by two normal faults, that has dropped downward in relation to adjacent portions.

Graben, from Ger. Graben "ditch, trench;" O.H.G. graban "ditch," grab "grave, tomb;" Goth. graban "ditch;" P.Gmc. *graban; cf. O.E. græf "grave, ditch;" E. a grave; PIE base *ghrebh-/*ghrobh- "to dig, to scratch, to scrape."

Foruzamin, from foru- + zamin. The first component foru- "down, downward; below; beneath;" Mid.Pers. frôt "down, downward;" O.Pers. fravata "forward, downward;" cf. Skt. pravát- "a sloping path, the slope of a mountain." The second component zamin, variant zami "earth, ground," from Mid.Pers. zamig "earth;" Av. zam- "the earth;" cf. Skt. ksam; Gk. khthôn, khamai "on the ground;" L. homo "earthly being" and humus "the earth" (as in homo sapiens or homicide, humble, humus, exhume); PIE root *dh(e)ghom "earth."

1) A degree or step in a scale, as of rank, advancement, quality, value, or intensity.
2) To arrange in a series of grades; class; sort (Dictionary.com).

From Fr. grade "grade, degree," from L. gradus "step, pace, gait, walk;" figuratively "a step, stage, degree," related to gradi "to walk, step, go," and second element in congress, progress, etc.; from PIE *ghredh-; cf. Lith. gridiju "to go, wander," O.C.S. gredo "to come," O.Ir. in-greinn "he pursues."

Padâk, from Baluci padâk "step, stair, ladder" (ultimately from Proto-Ir. *padaka-), older form of Pers. pâyé "step, base," from Mid.Pers. pâd, pây; Av. pad-, cf. Skt. pat: Gk. pos, genitive podos; L. pes; PIE *pod-/*ped-.

1) General: Degree of slope.
2) Physics: Change in the value of a quantity (as temperature, pressure) with change in a given variable.
3) Math.: A differential → operator (symbol → nabla, ∇) that, operating upon a function (f) of several variables, creates a → vector whose coordinates are the → partial derivatives of the function: ∇f = (∂f/∂x)i + (∂f/∂y)j + (∂f/∂z)k. The gradient of a → scalar function is a vector function.

From L. gradient-, gradiens, pr.p. of gradi "to walk, go," from grad- "walk" + -i- thematic vowel + -ent suffix of conjugation.

Ziné "ladder, steps, stair," may be related to ciné, from cidan "to place (something) above/upon (another similar thing);" cf. Lori râ-zina, Yazdi râ-cina "stairs," Nâyini orcen "stairs, ladder;" the phoneme change -c- into -z-, as in gozidan, gozin-/cidan, cin- both deriving from Proto-Ir. *cai- "to heap up, gather, collect."

Proceeding, taking place, changing by small degrees.

From M.L. gradualis, from L. gradus "step."

Padâkvâr, from padâk "grade," + -vâr a suffix which denotes "suiting, befitting, resembling, in the manner of, possession."
Pâypâyé "step by step," from pây, pâ "foot, step," → foot.

A burst that happens gradually, in contrast to a sudden burst.

→ gradual; → burst.

1) To divide into or mark with degrees or other divisions, as the scale of a thermometer.
2) To receive a degree or diploma on completing a course of study (often followed by from).
3) To confer a degree upon, or to grant a diploma to, at the close of a course of study, as in a university, college, or school.
4) A person who has received a degree or diploma on completing a course of study, as in a university, college, or school (Dictionary.com).

M.E., from M.L. graduatus, p.pa. of graduari "to take a degree," from L. gradus "step, → grade."

1, 3) Padâk dâdan, compound infinitive, padâkidan simple infinitive, both from padâk, → grade, + dâdan "to give, grant," → datum, and -idan, → -fy.
2) Padâk gereftan, from padâk + gereftan "→ take, hold."
4) Padâkmand, from padâk + -mand suffix of possession and ability, → -al; padâkidé, p.p. of padâkidan, as above.

1) Marking the scale of an instrument, e.g. the stem of a thermometer is graduated in degrees.
2) An act of graduating; the state of being graduated.

Verbal noun of → graduate.

1) A small, hard seed of plants, especially the seed of cereals.
2) A tiny portion or particle of something such as sand or salt; → dust grain.

M.E. grain, grein, from O.Fr. grein, from L. granum "seed;" akin to corn.

Dâné "grain, seed;" Mid.Pers. dân, dânag "seed, corn;" Av. dānô- in dānô.karš- "carrying grains; an ant;" cf. Skt. dhânâ- "corn, grain;" Tokharian B tāno "grain;" Lith. duona "corn, bread."

Sticking together of micron- to centimetre-sized grains occurring in the interstellar and protoplanetary environments to form larger grain agglomerates.

→ grain; → coagulation.

Conversion of dust grains into smaller grains due to high environmental temperatures.

→ grain; → evaporation.

The process by which dust grains are assembled or produced.

→ grain; → formation.

The increase of dust grains to micron sizes in the interstellar environments due to various physical processes, for example mutual collisions and accumulation of ice mantles.

→ grain; → growth.

A layer of icy molecules covering interstellar dust grains.

→ grain; mantle, from O.E. mentel "loose, sleeveless cloak," from L. mantellum "cloak," perhaps from a Celtic source.

Rupuš "overgarment, cloak," from ru "surface, face; aspect; appearance" (Mid.Pers. rôy, rôdh "face;" Av. raoδa- "growth," in plural form "appearance," from raod- "to grow, sprout, shoot;" cf. Skt. róha- "rising, height") + puš "covering, mantle," from pušidan "to cover; to put on" (Mid.Pers. pôšidan, pôš- "to cover; to wear;" cf. Mid.Pers. pôst; Mod.Pers. pust "skin, hide;" O.Pers. pavastā- "thin clay envelope used to protect unbaked clay tablets;" Skt. pavásta- "cover," Proto-Indo-Iranian *pauastā- "cloth").

The ejection of atoms from interstellar dust grains due to impact by gas ions, which leads to grain destruction.

→ grain; sputtering, from sputter "to spit with explosive sounds," cognate with Du. sputteren.

Osparâni, verbal noun of osparândan, from os- "out of, outside," → ex- + parândan "to eject," transitive of paridan "to fly" (from Mid./Mod.Pers. par(r) "feather, wing," Av. parəna- "feather, wing;" cp. Skt. parna "feather," E. fern; PIE *porno- "feather").

A unit of mass equal to one thousandth of a kilogram.

From Fr. gramme, from L.L. gramma "small weight," from Gk. gramma "small weight," originally "letter of the alphabet," from stem of graphein "to draw, write."

Geram, loanword from Fr. gramme, as above.

1) The study of the way the sentences of a language are constructed; → morphology and → syntax.
2) These features or constructions themselves (Dictionary.com).

M.E. gramarye, from O.Fr. gramaire "grammar; learning," especially Latin and philology, an "irregular semi-popular adoption" of L. grammatica, from Gk. grammatike (tekhne) "(art) of letters" with a sense of both philology and literature, from grammatikos "pertaining to or versed in letters or learning," from gramma "letter," → -gram.

Dastur-e zabân, literally "language rule," from dastur "rule; mandate, command; religious authority (of the Zoroastrians);" Mid.Pers. dast "able, capable;" Av. danh- "to teach, instruct;" cf. Skt. dams- "to show or teach wonderful skills, perform wise;" Gk. didasko "I learn;" PIE *dens- "to become skilfull; to teach, instruct" (Cheung 2007); + zabân, → language.