astro- Look up astro- at
element active in English word formation from mid-18c. and meaning "star or celestial body; outer space," from Greek astro-, stem and comb. form of astron "star," related to aster "star" (see star (n.)). In ancient Greek, aster typically was "a star" and astron mostly in plural, "the stars." In singular it mostly meant "Sirius" (the brightest star).
astrobiology (n.) Look up astrobiology at
1903, from French astrobiologie; see astro- + biology. Related: Astrobiological; astrobiologist.
astrobleme (n.) Look up astrobleme at
1961, from astro- + Greek bleme "throw of a missile; wound caused by a missile," from ballein "to throw" (see ballistics).
astroid (adj.) Look up astroid at
"star-shaped," 1897, from Greek astroeides, from astron "star" (see astro-) + -oeides (see -oid).
astrolabe (n.) Look up astrolabe at
mid-14c., from Old French astrelabe, from Medieval Latin astrolabium, from Greek astrolabos (organon) "star taking (instrument)," from astron "star" (see astro-) + lambanien "to take" (see analemma).
astrologer (n.) Look up astrologer at
late 14c., from astrology + -er (1). Drove out French import astrologein, which, had it survived, probably would have yielded *astrologian, as in Chaucer's "The wise Astrologen." Earliest recorded reference is to roosters as announcers of sunrise.
astrological (adj.) Look up astrological at
1590s; see astrology + -ical. Related: Astrologically.
astrology (n.) Look up astrology at
late 14c., from Latin astrologia "astronomy, the science of the heavenly bodies," from Greek astrologia "telling of the stars," from astron "star" (see astro-) + -logia "treating of" (see -logy).

Originally identical with astronomy, it had also a special sense of "practical astronomy, astronomy applied to prediction of events." This was divided into natural astrology "the calculation and foretelling of natural phenomenon" (tides, eclipses, etc.), and judicial astrology "the art of judging occult influences of stars on human affairs" (also known as astromancy, 1650s). Differentiation between astrology and astronomy began late 1400s and by 17c. this word was limited to "reading influences of the stars and their effects on human destiny."
astronaut (n.) Look up astronaut at
coined 1929 in science fiction, popularized from 1961 by U.S. space program, from astro- + nautes "sailor" (see naval). French astronautique (adj.) had been coined 1927 by "J.H. Rosny," pen name of Belgian-born science fiction writer Joseph Henri Honoré Boex (1856-1940) on model of aéronautique, and Astronaut was used in 1880 as the name of a fictional spaceship by English writer Percy Greg (1836-1889) in "Across the Zodiac."
astronautics (n.) Look up astronautics at
1929, see astronaut + -ics.
astronomer (n.) Look up astronomer at
late 14c., from astronomy (q.v.), replacing French import astronomyen (c. 1300), which, had it survived, probably would have yielded *astronomian. Still in Shakespeare used in places where we would write astrologer.
astronomical (adj.) Look up astronomical at
1550s, from astronomy + -ical. Popular meaning "immense, concerning very large figures" (as sizes and distances in astronomy) is attested from 1899. Astronomical unit (abbreviation A.U.) "mean distance from Earth to Sun," used as a unit of measure of distance in space, is from 1909. Related: Astronomically.
astronomy (n.) Look up astronomy at
c. 1200, from Old French astrenomie, from Latin astronomia, from Greek astronomia, literally "star arrangement," from astron "star" (see astro-) + nomos "arranging, regulating," related to nemein "to deal out" (see numismatic). Used earlier than astrology and originally including it.
Þer wes moni god clarc to lokien in þan leofte, to lokien i þan steorren nehʒe and feorren. þe craft is ihate Astronomie. [Layamon, "The Brut," c. 1200]
astrophotography (n.) Look up astrophotography at
1858, from astro- + photography.
astrophysicist (n.) Look up astrophysicist at
1869, usually hyphenated at first, from astro- + physicist. Astrophysics is recorded from 1877.
Astroturf (n.) Look up Astroturf at
1966, proprietary name for a kind of artificial grass, so called because it was used first in the Houston, Texas, Astrodome, indoor sports stadium. See astro- + turf. Houston was a center of the U.S. space program.
astute (adj.) Look up astute at
1610s, from Latin astutus "crafty, wary, shrewd; sagacious, expert," from astus "cunning, cleverness, adroitness," which is of uncertain origin, perhaps from Greek asty "town," a word borrowed into Latin and with an overtone of "city sophistication" (compare asteism). Related: Astutely; astuteness.
Astyanax Look up Astyanax at
son of Hector and Andromache ("Iliad"), Greek, literally "lord of the city," from asty "city" (see asteism) + anax "chief, lord, master." Also the epithet of certain gods.
asunder (adv.) Look up asunder at
mid-12c., contraction of Old English on sundran (see sunder). Middle English used to know asunder for "distinguish, tell apart."
asylum (n.) Look up asylum at
early 15c., earlier asile (late 14c.), from Latin asylum "sanctuary," from Greek asylon "refuge," noun use of neuter of asylos "inviolable, safe from violence," especially of persons seeking protection, from a- "without" + syle "right of seizure." So literally "an inviolable place." General sense of "safe or secure place" is from 1640s; meaning "benevolent institution to shelter some class of persons" is from 1776.
asymmetrical (adj.) Look up asymmetrical at
1680s; see asymmetry + -ical. Other forms that have served as an adjective based on asymmetry are asymmetral (1620s), asymmetrous (1660s), and asymmetric (1875); only the last seems to have any currency. Related: Asymmetrically.
asymmetry (n.) Look up asymmetry at
1650s, "want of symmetry or proportion," from Greek asymmetria, noun of quality from asymmetros "having no common measure; disproportionate, unsymmetrical," from a- "not" + symmetros "commensurable" (see symmetry).
asymptomatic (adj.) Look up asymptomatic at
"without symptoms," 1856, from a-, privative prefix, + symptomatic.
asymptote (n.) Look up asymptote at
"straight line continually approaching but never meeting a curve," 1650s, from Greek asymptotos "not falling together," from a- "not" + syn "with" + ptotos "fallen," verbal adjective from piptein "to fall" (see symptom). Related: Asymptotic.
asymptotic (adj.) Look up asymptotic at
1670s, see asymptote + -ic. Related: Asymptotical; asymptotically.
asynchronous (adj.) Look up asynchronous at
1748, from a-, privative prefix, + synchronous.
asyndetic (adj.) Look up asyndetic at
1823; see asyndeton + -ic.
asyndeton (n.) Look up asyndeton at
"omission of conjunctions," 1580s, from Latin, from Greek asyndeton, neuter of asyndetos "unconnected," from a-, privative prefix (see a- (3)), + syndetos, from syndein "to bind together," from syn- "together" (see syn-) + dein "to bind," related to desmos "band," from PIE *de- "to bind."
asystole (n.) Look up asystole at
1860, from Modern Latin, from Greek a-, privative prefix (see a- (3)), + systole "contraction" (see systole).
at (prep.) Look up at at
Old English æt, from Proto-Germanic *at (source also of Old Norse, Gothic at, Old Frisian et, Old High German az), from PIE *ad- "to, near, at" (source also of Latin ad "to, toward" Sanskrit adhi "near;" see ad-).

Lost in German and Dutch, which use their equivalent of to; in Scandinavian, however, to has been lost and at fills its place. In choosing between at church, in church, etc. at is properly distinguished from in or on by involving some practical connection; a worshipper is at church; a tourist is in the church.

The colloquial use of at after where ("where it's at") is attested from 1859. At last is recorded from late 13c.; adverbial phrase at least was in use by 1775. At in Middle English was used freely with prepositions (as in at after, which is in Shakespeare), but this has faded with the exception of at about, which was used in modern times by Trollope, Virginia Woolfe, D.H. Lawrence, and Evelyn Waugh, but nonetheless is regarded as a sign of incompetent writing by my copy editor bosses.
at all Look up at all at
"in any way," mid-14c., originally used only affirmatively (as in I Samuel xx.6 in KJV: "If thy father at all misse me"); now it is overwhelmingly used only in the negative or in interrogatory expressions, or in literary attempts at Irish dialect.
at bay Look up at bay at
late 14c., originally often at the bay; see bay (n.3). Figurative use, of human beings in difficulties, is from c. 1400. The expression reflects the former more widespread use of at. Earlier the expression be at abai was used of the hunted animal, "be unable to escape," c. 1300, from French.
at- Look up at- at
assimilated form of ad- "to, toward, before" before stems beginning in -t-; see ad-.
at-bat (n.) Look up at-bat at
"baseball player's turn at the plate," 1912, originally a column heading in statistics tables.
at-home (n.) Look up at-home at
"reception of visitors," 1745, from phrase at home.
Atalanta Look up Atalanta at
in Greek mythology the daughter of king Schoeneus, famous for her swiftness, Latin, from Greek Atalante, fem. of atalantos "having the same value (as a man)," from a- "one, together" + talanton "balance, weight, value" (compare talent).
ataractic (adj.) Look up ataractic at
1941, from Greek ataraktos "not disturbed" (see ataraxia) + -ic.
ataraxia (n.) Look up ataraxia at
also Englished as ataraxy, "calmness, impassivity," c. 1600, from Modern Latin, from Greek ataraxia "impassiveness," from a-, privative prefix, + tarassein (Attic tarattein) "to disturb, confuse," from PIE root *dher- (1) "to make muddy, darken."
atavic (adj.) Look up atavic at
"pertaining to a remote ancestor," 1866, from Latin atavus "ancestor" (see atavism) + -ic.
atavism (n.) Look up atavism at
1833, from French atavisme, attested by 1820s, from Latin atavus "ancestor, forefather," from at- perhaps here meaning "beyond" + avus "grandfather," from PIE *awo- "adult male relative other than the father" (see uncle).
atavistic (adj.) Look up atavistic at
"pertaining to atavism," 1847; see atavism + -ic.
ataxia (n.) Look up ataxia at
also Englished as ataxy, "irregularity of bodily functions," 1610s, "confusion, disorder," medical Latin, from Greek ataxia, from a-, privative prefix, + taxis "arrangement, order," from stem of tassein "to arrange" (see tactics). Pathological sense is attested from 1660s.
ataxic (adj.) Look up ataxic at
1853, from ataxia + -ic.
atchoo Look up atchoo at
imitative of the sound of sneezing, first attested 1873, as atcha (a-tschoo is from 1878).
ate Look up ate at
past tense of eat (q.v.).
Ate Look up Ate at
Greek goddess of infatuation and evil, from ate "damage, ruin; guilt; blindness, dazzlement, infatuation; penalty, fine," which is of uncertain origin.
atelectasis (n.) Look up atelectasis at
"incomplete expansion of the lungs," 1836, medical Latin, from Greek ateles "imperfect, incomplete," literally "without an end," (from a-, privative prefix, + telos "completion") + ektosis "extention." Related: Atelectatic.
atelier (n.) Look up atelier at
1840, from French atelier "workshop," from Old French astelier "(carpenter's) workshop, woodpile" (14c.), from astele "piece of wood, a shaving, splinter," probably from Late Latin hastella "a thin stick," diminutive of hasta "spear, shaft" (see yard (n.2)).
atemporal (adj.) Look up atemporal at
1870, from a- "not" + temporal. Related: Atemporally.
Aten Look up Aten at
a name of the sun in ancient Egypt, from Egyptian itn.