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

1) General: Something shaped like a → curve or → arch.
2) Math.: A → segment of a → circle.
3) Electricity: A continuous luminous → discharge across a gap between two → electrodes, as in an arc lamp. → electric arc.
4) Astro.: The apparent path of a celestial body above and below the horizon.

M.E. ark, from M.Fr. arc "bow," from L. arcus "bow, arch" (cf. Goth. arhwazna "arrow," O.E. earh), PIE *arqu- "bowed, curved."

Kamân "arc, bow" from Mid.Pers. kamân, related to xam "curve," cf. Breton kamm "curved, bent," Gk. kampe "a corner, a joint," L. campus "a field," Lith. kampus "corner," PIE *kamb- "to bend, crook."

A unit of angular size equal to 1/60 of a degree.

→ arc; → minute.

The apparent angular separation (→ elongation) between the → centers of the → Sun and the → Moon.

→ arc; → light.

The difference in → right ascension between the → Sun and the → Moon, measured in degrees.

→ arc; → separation.

The → angular  → difference in → altitude between the → Sun and the → Moon.

→ arc; → vision.

A unit of angular size equal to 1/3.600 of a degree.

→ arc; → second.

The spectrum produced by an atom or mixture of atoms as a result of vaporization within an electric arc generated between two electrodes.

→ arc; → spectrum.

1) A curved structure, normally in the vertical plane, that spans an opening.
2) Any overhead curvature resembling an arch. → Arches cluster.

M.E. arch(e), from O.Fr. arche "arch of a bridge," from L. arcus "a bow," → arc.

Taq "arch," from tâk, contraction of târak, → vertex.

Any of the four vaulted structures in the foot: the internal (medial) longitudinal, the outer (lateral) longitudinal, and two transverse (Medical Dictionary, Farlex).

→ arch; → foot.

The study that deals with the astronomical knowledge of prehistoric peoples (season events, calendars, observing sites, astronomical alignments) and its influence on their cultures and societies (mythologies, religions, life). Archaeoastronomy covers the intersection between astronomy and archaeology. Same as → astroarchaeology, megalithic astronomy.

Archeoastronomy, from L. archaeo-, archeo "ancient; earlier; primitive," from Gk. arkhaio-, from arkhaios "ancient" + → astronomy.

Bâstânaxtaršenâsi, from bâstân "ancient" + axtaršenâsi, → astronomy.

A prefix meaning "principal, prior, original, first, early" Same as archi-. → archetype.

From Gk. arkhe-, from arckhon "ruler," noun use of p.p. of arkhein "to rule."

Sar-, from sar "top, summit, the capital of a pillar," → head.

One of the three → Galactic center clusters supposed to be the densest young → massive star cluster in the Milky Way. It contains the richest collection of → O stars and → WN Wolf-Rayet stars in any cluster in the Galaxy, thus representing the largest collection of the most massive stars in the Galaxy. With its estimated age of 2-3 million years, the Arches cluster is the youngest of the massive clusters in the Galactic center. → Quintuplet cluster; → Central cluster (Figer et al. 2002, ApJ 581, 258; and 1999, ApJ 525, 750).

Arches, from the presence of Galactic center thermal → arched filaments, about 100 → light-years in projection from the Galactic center (Morris & Yusef-Zadeh, 1985, AJ 90, 2511), from M.E. arche, O.Fr. arche "arch of a bridge," from L. arcus, → arc; → cluster.

The original pattern or model from which all things of the same kind are copied or on which they are based; a model or first form; prototype (Dictionary.com).

→ arche-; → type.

A body immersed totally or partially in a liquid is buoyed up by a force equal to the weight of the liquid displaced by the body. → buoyancy.

Archimedes of Syracuse (c. 287 BC - c. 212 BC), Greek mathematician and inventor; → principle.

Arašmidos altered form of Archimedes in classical Ar. texts; parvaz, → principle.

1) The art or practice of designing and building structures.
2) Computers: The arrangement of the various devices in a computer system or network. See also → software architecture.

M.E., from M.Fr. architecture, from L. architectura, from architectus "architect," from Gk. arkhitekton "master builder, director of works," from arkhi- "chief" + tekton "builder, carpenter," → technique.

Mehrâzik, from mehrâz literally "chief mason," from meh- "great, large," → high, + râz "mason, builder" (Borhân-e Qâte'), from Mid.Pers. râz "builder, architect," probably related to O.Pers. râs-, Av. râz- "to direct, set, put in line" (with many cognates in Pers., such as râst "straight, direct, true;" raj, rak, râk, rezg (Lori), radé, râdé "line, rule, row," rasté, râsté "row, a market with regular ranges of shops;" ris, risé "straight"); 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;" Ger. recht; E. right; PIE base *reg- "move in a straight line," hence, "to direct, rule;" + -ik, → -ics.

Any extensive record or collection of data.

Archive, from Fr. archives, from L. archivum, from Gk. arkheion "government house, town hall," from arkhe "government," from arkhein "to rule".

Bâygâni, maybe from *pâygâni, from pây-, pâyidan "to watch, guard, take care, conserve" + -gân, suffix referring to group, collection, + -i, noun-forming suffix.

An angular measurement equal to 1/60 of a degree. It is denoted by the symbol '.

→ arc; → minute.

An angular measurement equal to 1/3600 of a degree or 1/60 of an arcminute. It is denoted by the symbol ''. There are 206,264.5'' in a radian, so that 1'' = 4.848 × 10^-6 radians.

→ arc; → second.

The north polar area, north of latitude 66° 33' 8'' N.

Arctic, from O.Fr. artique, from L. arcticus, from Gk. arktikos "of the north," literally "of the (northerly prominent constellation) Bear," from arktos "bear" (cf. Av. arša-, Mod.Pers. xers, Tabari aš, Skt. rksa, L. ursus; PIE *rtko-).

Hudargân, from hudar, → north, + -gân prefix denoting the direction.
Šomâlgân, from šomâl "north," from Ar. šemâl "north, left"+ -gân.

The fourth brightest star in the sky (V magnitude -0.06) lying in the constellation → Boötes at a distance of about 35 light-years. Arcturus is a red giant of spectral type K2 IIIp.

L. Arcturus, from Gk. Arktouros "guardian of the bear," arktos "bear," → Arctic + ouros "guardian, watcher".

Xersbân "guardian of the bear," from xers "bear" (Mid.Pers. xirs, Av. arša-, cognate with Gk. arktos, Skt. rksa, L. ursus; PIE *rtko-) + -bân suffix meaning "watcher, keeper, guard".
Ar. Semâk-e râmeh.