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

The officials or office entrusted with administrative duties, maintaining records, and overseeing or performing secretarial duties, especially for an international organization (Dictionary.com).

From Fr. secrétariat, from M.L. secretariatus, from secretarius, → secretary.

Dabirxâné, literally "house of secretaries," from dabir, → secretary, + xâné, → house.

A person, usually an official, who is in charge of the records, correspondence, minutes of meetings, and related affairs of an organization, company, association, etc. (Dictionary.com).

M.E. secretarie "one trusted with private or secret matters; confidant," from M.L. secretarius "confidential officer, confidant, clerk, notary," from L. secretum "a secret, a hidden thing."

Dabir, from Mid.Pers. dipîr, contraction of dipîvar (Mid.Pers. dip, dīp "document;" dīb "letter"); from O.Pers., from Proto-Ir. *dipī-uara- "he who preserves the documents;" cf. O.Pers. dipī- "inscription" + *Huar- "to cover;" cf. Av. vār- "to cover, hide, protect."

The head or chief administrative officer of a secretariat.

→ secretary; → general.

A part that is cut off or separated.
A distinct part or subdivision of anything. → cross section; → intersection

From M.Fr. section, from L. sectionem "a cutting, division," from secare "to cut;" PIE base *sek- "cut" (cf. O.C.S. seko, sesti "to cut," Lith. isekti "to engrave, carve;" O.S. segasna, O.E. sigðe "scythe;" O.E. secg "sword," seax "knife, short sword").

Sekanj "a scraping, shaving, cutting," cognate with Pers. šekast-, šekastan "to break;" Av. skand- "to break," Skt. khand- "to break," khanda- "piece;" Pers. dialect Tabari šag "a special razor used to make incisions in the walls of unripe opium poppies in order to extract the milky sap," may be related to PIE *sek- "cut," as above.

1a) General: Going on from age to age; continuing through long ages.
1b) Astro.: Gradual or taking place over a long period. → secular acceleration; → secular change.
2a) (adj.) Worldly or material rather than spiritual.
2b) (adj.) Not overtly or specifically relating to religion or to a religious body.
2c) (adj. & n.) Relating to or advocating secularism; a layperson.

Secular from O.Fr. seculer, from L.L. sæcularis "of an age, occurring once in an age," from sæculum "age, span of time, generation, the spirit of the age."

1) Diryâz "long lasting, from dir "slowly, tardily; late" (Mid.Pers. dêr, variants dagr, drâz "long;" (Mod.Pers. derâz "long," variant Laki, Kurdi derež); O.Pers. darga- "long;" Av. darəga-, darəγa- "long," drājištəm "longest;" cf. Skt. dirghá- "long (in space and time);" L. longus "long;" Gk. dolikhos "elongated;" O.H.G., Ger. lang; Goth. laggs "long;" PIE base *dlonghos- "long") + yâz present stem of yâzidan "to stretch out the arms; grow up" (Parthian Mid.Pers. y'd "to reach a goal, come to, stretch out;" Av. yat- to reach, take one's place," yaiiata "places," frā-iiatāt "has reached;" cf. Skt. yat- "to be in place, put in place, line up;" PIE base *iet- "to be in place").
2) Giyâné, giyâni from giyân, variant of Mod.Pers. jahân, keyhân, geyhân "world," giti "world, material world, time," Mid.Pers. gêhân "world," gêtig "the material world; wordly," Manichean Mid.Pers. gyh "world," gyh'n "worlds;" Av. gaē&thetaā- "being, world, matter, mankind," gaya- "life, manner of living", root gay- "to live" (present tense jiva-), O.Pers. gaiθā- "live-stock," cognate with Skt. jīv- "to live," jīva- "alive, living;" Gk. bios "life," L. vivus "living, alive," vita "life;" PIE base *g^wei- "to live" (cf. O.E. cwic "alive;" O.C.S. zivo "to live;" Lith. gyvas "living, alive;" O.Ir. bethu "life," bith "age, life, world;" Welsh byd "world"). The Pers. words zistan "to live," zendé "alive," zendegi "life," and jân "vital spirit, soul; mind" belong to this family.

The smallest component of the aberration of starlight which is caused by the motion of the solar system through space. → annual aberration; → diurnal aberration.

→ secular; → aberration.

The apparent gradual increase in the → Moon's motion in its orbit, as measured relative to → mean solar time. Secular acceleration corresponds to an extremely gradual reduction in the speed of the → Earth's rotation. The slow-down of the Earth's spin comes mainly from → tidal frictions from the Moon. Historically, Edmond Halley (1656-1742) was the first to suggest that the Moon's mean rate of motion relative to the stars was gradually increasing. In 1693, Halley compared eclipses of recent, medieval, and classical Babylonian time, and discovered that the Moon's mean motion had been gradually increasing. Using Lunar Laser Ranging measurement, based on laser reflectors left by the Apollo astronauts on the Moon's surface (1969 to 1972), the secular acceleration is derived to be -25".4 ± 0".1 century ² (Xu Huaguan et al., 1996, in Earth, Moon and Planets 73, 101). This corresponds to a linear increase of about 3.5 cm yr^-1 in the mean Earth-Moon distance.

→ secular; → acceleration.

A continuous, non-periodic change in one of the attributes of the states of a system. Often, a change in an orbit due to dissipation of energy. See also → canonical change.

→ secular; → change.

Instability caused by a slow dissipation of energy.

→ secular; → instability.

The angle subtended at a star by a baseline that is the distance the Sun moves in a given interval of time with respect to the local standard of rest (4.09 AU per year).

→ secular; → parallax.

A variation of planetary orbital elements which is always in the same direction as time increases.

→ secular; → perturbation.

1) The condition in which the equilibrium configuration of a system is stable over long periods of time.
2) The condition of a star when it is stable against arbitrary adiabatic perturbations.

→ secular; → stability.

In perturbation theory used in celestial mechanics, a steadily increasing disturbance. → periodic term.

→ secular; → term.

Same as → secular perturbation.

→ secular; → variation.

The view that religious considerations should be excluded from civil affairs or public education.

→ secular.

The process of organizing society or aspects of social life around non-religious values or principles.

Verbal noun of secularize "giyânidan" (گیانیدن); → secular

1) Free from or not exposed to danger or harm; safe.
2) To get hold or possession of; procure; obtain.

From L. securus "free from care, quiet, easy," also "careless, reckless;" of things, "free from danger, safe," from *se cura, from se "without, free from," + cura, → care.

Zilé, from Tabari zil, zilé "firm, fixed," zil hâkerdan "to fix, fasten," of unknown origin.

1) Freedom from care, anxiety, or doubt; well-founded confidence.
2) Something that secures or makes safe; protection; defense.
3) A department or organization responsible for protection or safety (Dictionary.com).

→ secure; → -ity.

A technique that uses → spectral energy distribution results from models to reproduce observational data.

→ spectral energy distribution; → fitting.

Mineral or organic material which has been transported and deposited by an agent of erosion such as water, wind, and ice.

From Fr. sédiment, from L. sedimentum "a settling, sinking down," from stem of sedere "to settle, sit"

Nehešt past stem of neheštan "to place, deposit," from ne- "down, below," → ni- (PIE), + heštan "to place, put" from Mid.Pers. hištan, hilidan "to let, set, leave, abandon;" Parthian Mid.Pers. hyrz; O.Pers. hard- "to send forth," ava.hard- "to abandon;" Av. harəz- "to discharge, send out; to filter," hərəzaiti "releases, shoots;" cf. Skt. srj- "to let go or fly, throw, cast, emit, put forth;" Pali sajati "to let loose, send forth."