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

A rare kind of → meteorite containing the → enstatite mineral. These meteorites are thought to comprise only about 2% of the chondrites that fall on Earth. Also called → E-type chondrite.

→ enstatite; → chondrite.

To wrap or twist together; to intertwine.

From → en- "in," + tangle, from M.E. tangilen, tagilen "to entangle."

Hamgureš, from ham- "together," → com-, + guridan "to become tangled, as threads or hairs, entwine," probably related to greh "knot," → node.
Hampicidan, from ham- + picidan "to twist, entwine, coil."

The act of entangling. The state of being entangled.

Verbal noun of → entangle; → -ment.

1) To come or go in.
2) To put in or insert. See also → entrance, → entry.

M.E. entren, from O.Fr. entrer, from L. intrare "to enter," from intra "within," → inter-.

Darâmadan, from dar, → in-, + âmadan, "to come," → egress; darâyidan, from dar- "in," + ây preset stem of âmadan, → assembly, + -idan infinitive suffix; darâyândan transitive of darâyidan.

A quantity associated with a thermodynamic system and given by H = U + pV, where H is the enthalpy, U the internal energy, p the pressure, and V the volume.

Gk. enthalp(ein) "to warm in," from en- "in, into, within" + thalpein "to warm" + -y a suffix used in the formation of action nouns from verbs.

Darungarmi, from darun "in, into, within" (Mid.Pers. andarôn "inside," from andar, → inter- + rôn "side, direction;" Av. ravan- "(course of a) river") + garm "warm" (Mid.Pers. garm; O.Pers./Av. garema- "hot, warm;" cf. Skt. gharmah "heat;" Gk. thermos "warm;" L. formus "warm," fornax "oven;" P.Gmc. *warmaz; O.E. wearm; O.H.G., Ger. warm; from PIE base *ghworm-/*ghwerm-) + -i a suffix used in the formation of action nouns from verbs.

To give a particular title to.

From en-, → in-, + → title.

Having the title.

Past participle of → entitle.

1) A real thing.
2) Being or existence, especially when considered as independent, separate, or self-contained.
3) Computer science: Something about which data is recorded. Entities have → attributes.

From L.L. entitatem, from L.L. ens (genitive entis) "being, thing," from esse "to be," cognate with Pers. hast, ast, as below.

Hastâr, from hast (noun), as in hast-o-nist, or contraction of hasti "existence," from hastan "to be" (variant astan, ast "is;" Mid.Pers. (h)ast "is," (h)astih "existence;" O.Pers. ah- "to be," astiy "is;" Av. ah- "to be" (ahmī, ahī, astī); cf. Skt. as- "to be," ásti "is;" Gk. esti "is;" L. est "is;" Russ. yest "is;" Goth. ist; E. is), + suffix -âr (as in padidâr). Alternatively, from hast (noun), as above, + -âr contraction of -dâr (as in dustâr) present stem of dâštan "to have, to possess" (Mid.Pers. dâštan, O.Pers./Av. root dar- "to hold, keep back, maintain, keep in mind," Skt. dhr-, dharma- "law," Gk. thronos "elevated seat, throne," L. firmus "firm, stable," Lith. daryti "to make," PIE *dher- "to hold, support").

1) An act of entering, as into a place or upon new duties.
2) A point or place of entering; an opening or passage for entering, as a doorway (Dictionary.com). → entrance pupil, → entrance slit.

M.E. entraunce, from M.Fr. entrance, from → enter + → -ance.

Darâyeš, verbal noun of darâmadan, darâyidan, → enter; darâygâh with space suffix -gâh.

In an → optical system, the image of the → aperture stop formed in → object space. See also → exit pupil.

→ entrance; → pupil.

A thin slit in an opaque screen by which light enters a spectrograph.

→ entrance; → slit.

1) A measure of the energy that is not available for work during a → thermodynamic process. It is defined by dS = dQ/T, where dS is the differential change in entropy, dQ is the differential amount of heat introduced to the system in a → reversible process, and T the → absolute temperature of the system. Entropy remains constant during → reversible processes and increases during → irreversible processes without ever decreasing. According to the → second law of thermodynamics, an → isolated system evolves toward a state of maximum entropy. See also → Maxwell's demon.
2) Statistical physics: A measure of → disorder of the configuration of → microstates which make up a → macrostate. → Boltzmann's relation, → Boltzmann's entropy formula. Highly disordered systems have a large entropy; highly ordered systems have low entropy.
3) Math.: A measure of information content. → information entropy.

From Ger. Entropie, coined 1865 by physicist Rudolf Clausius (1822-1888) from Gk. entropia "a turning toward," from en- "in" + trope "a turning, change," related to tropos "a turn, way, manner," from tropein "to turn," from PIE base *trep- "to turn" (cf. L. trepit "he turns").

Dargâšt, from dar "in" + gâšt present stem of gâštan "to cause to revolve, to turn," transitive of gaštan, variant gardidan "to turn, to change" (Mid.Pers. vartitan; Av. varət- "to turn, revolve;" cf. Skt. vartati; L. vertere; O.H.G. werden "to become;" PIE base *wer- "to turn, bend").

1) An act of entering; → entrance.
2) Permission or right to enter; access.
3) A place of ingress or entrance, especially an entrance hall or vestibule.
4) The act of entering or recording something in a book, register, list, etc. The statement, item, etc., so entered or recorded (Dictionary.com).

M.E. entre(e), from O.Fr. entree, from L. intrata, p.p. of intrare "to → enter."

Darâyé, noun from darây present stem of darâmadan, darâyidan, → enter, + -é noun suffix.

A shell of dust or gas expanding out from an astronomical object such as a star or a comet's nucleus.

From Fr. enveloppe, from O.Fr. envoloper "to envelop," from en- "in" + voloper "wrap up," of obscure origin, perhaps related to M.L. aluppa "a very thin piece or slice of wood" and influenced by L. volvere "to roll."

Pušé, noun 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."

1) An aggregate of surrounding → circumstances, → conditions, or → influences in which a thing is situated or is developed.
2) Computers: The entire set of conditions under which one operates a → computer, as it relates to the hardware, operating platform, or operating system.
3) Ecology: The totality of circumstances surrounding an → organism or group of organisms. More specifically, the combination of external physical conditions that affect and influence the growth, development, and survival of organisms.

From environ + -ment; the first component from Fr. environs, plural of O.Fr. environ "compass, circuit," from environ (adv.) "around," from en- "in" + viron "circle, circuit," from virer "to turn."

Pargir, from par- "around, surrounding," variant pirâ-→ circum- + gir agent noun and present stem of gereftan "to take, seize; to make prisoner; to intercept" (Mid.Pers. griftan; Av./O.Pers. grab- "to take, seize;" cf. Skt. grah-, grabh- "to seize, take," graha "seizing, holding, perceiving;" M.L.G. grabben "to grab," from P.Gmc. *grab; E. grab "to take or grasp suddenly;" PIE base *ghrebh- "to seize").
Zistbum, from zist "life, existence," → bio-, + bum "region, land, place," → eco-.

1) The time that must be added to the lunar year (12 lunations) to make it coincide with the solar year (about 11 days).
2) The moon's age at the beginning of the calendar year.

From Fr. épacte, from L. epacta, from Gk. epaktos, verbal adj. of epagein "to intercalate, add, bring forward," from epi "on" + ag-, from agein "to bring, to lead;" cf. L. agere "to drive, set in motion," → act.

Barafzâ, from bar- "on, upon, up" (Mid.Pers. abar; O.Pers. upariy "above; over, upon, according to;" Av. upairi "above, over," upairi.zəma- "located above the earth;" cf. Gk. hyper- "over, above;" L. super-; O.H.G. ubir "over;" PIE base *uper "over") + afzâ, afzudan "to add, increase" (Mid.Pers. abzudan "to increase, grow;" O.Pers. abijav- "to increase, add to, promote," from abi-, aiby- "in addition to; to; against" + root jav- "to press forward;" Av. gav- "to hasten, drive;" Sk. jav- "to press forward, impel quickly, excite," javate "hastens").

In Old Iranian and Egyptian calendars and much later in the → French Republican Calendar, one of five (or six) days placed between the 30th of the last month and the first day of the new year to result in a fixed year of 365 (366) days every year; plural epagomenae. Same as → epagomenal day. See also → sansculottide.

From Gk. epagomenos "added," from epagein "to add, to intercalate," from → epi- "on" + agein "to bring, to lead," → act.

Andargâh "intercalary," literally "time between," from andar "between, among," → inter-, + gâh "time;" Mid.Pers. gâh; O.Pers. gāθu-; Av. gātav-, gātu- "place, throne, spot" (Skt. gátu- "going, motion; free space for moving; place of abode;" PIE *gwem- "to go, come").
Tarufté "intercalary," literally "stolen (day);" Mid.Pers. truftag, from taruftan "to steal," traft "stolen;" Mod.Pers. Lârestâni dialect toftak "spy;" Av. tarəp- "to steal," tarəfiiāt- "he would steal;" cf. Skt. tarp- "to steal, rob," paśu.trp- "stealing cattle."
Dozdidé "intercalary," literally "stolen (day)," p.p. of dozdidan "to steal," Mid.Pers. duz(d)itan, from duzd "thief," from Av. duždāo- "miscreant, villain."

Same as → epagomena.

→ epagomena + → -al; → day.

A table of computed positions occupied by a celestial body over successive intervals of time such as daily; plural ephemerides.

From L. ephemeris "day book, diary," from Gk. ephemeris "diary, account book," from ephemeros "short-lived, lasting but a day," from → epi "on, upon" + hemerai, dative of hemera "day."

Ruzij, from ruz, → day + zij "astronomical table," from Mid.Pers. zig "astronomical table," originally "string," since the lines of a table were compared to strings used on a weaver's instrument, variant zih, meaning "cord, string" (Modern Persian zeh "cord, string"); Av. jiiā- "bow-string;" cf. Skt. jiyā- "bow-string;" PIE base *g^whi- "thread, tendon" (from which derive also Gk. bios "bow;" L. filum "thread;" Russ. žca "thread").

86,400 → ephemeris seconds.

→ ephemeris; → day.