Australian (n.) Look up Australian at Dictionary.com
1690s, in reference to aboriginal inhabitants, from Australia + -an. As an adjective by 1814. Australianism in speech is attested from 1891.
Australopithecus (n.) Look up Australopithecus at Dictionary.com
1925, coined by Australian anthropologist Raymond A. Dart (1893-1988) from Latin australis "southern" (see Australia) + Greek pithekos "ape." So called because first discovered in South Africa.
Austria Look up Austria at Dictionary.com
European nation, from Medieval Latin Marchia austriaca "eastern borderland." German Österreich is "eastern kingdom," from Old High German ostar "eastern" (see east) + reich (see Reichstag). So called for being on the eastern edge of Charlemagne's empire.
Austro- Look up Austro- at Dictionary.com
comb. form meaning "Austrian;" see Austria.
autarchy (n.) Look up autarchy at Dictionary.com
1660s, "absolute sovereignty," from Greek autarkhia, from autarkhein "to be an absolute ruler," from autos "self" (see auto-) + arkhein "to rule" (see archon).
autarky (n.) Look up autarky at Dictionary.com
1610s, "self-sufficiency," from Greek autarkeia "sufficiency in oneself, independence," from autarkes "self-sufficient, having enough, independent of others" (also used of countries), from autos "self" (see auto-) + arkein "to ward off, keep off," also "to be strong enough, sufficient," from PIE root *ark- "to hold, contain, guard" (see arcane). From a different Greek source than autarchy, and thus the spelling. As a term in international economics, prominent late 1930s. Related: Autarkic.
auteur (n.) Look up auteur at Dictionary.com
1962, from French, literally "author" (see author (n.)).
authentic (adj.) Look up authentic at Dictionary.com
mid-14c., "authoritative," from Old French autentique (13c., Modern French authentique) "authentic; canonical," and directly from Medieval Latin authenticus, from Greek authentikos "original, genuine, principal," from authentes "one acting on one's own authority," from autos "self" (see auto-) + hentes "doer, being," from PIE *sene- "to accomplish, achieve." Sense of "entitled to acceptance as factual" is first recorded mid-14c.

Traditionally in modern use, authentic implies that the contents of the thing in question correspond to the facts and are not fictitious; genuine implies that the reputed author is the real one; but this is not always maintained: "The distinction which the 18th c. apologists attempted to establish between genuine and authentic ... does not agree well with the etymology of the latter word, and is not now recognized" [OED].
authenticate (v.) Look up authenticate at Dictionary.com
"verify, establish the credibility of," 1650s, from Medieval Latin authenticatus, past participle of authenticare, from authenticus (see authentic). Related: Authenticated; authenticating.
authentication (n.) Look up authentication at Dictionary.com
1788, noun of action from authenticate (v.).
authenticity (n.) Look up authenticity at Dictionary.com
1760; see authentic + -ity. Earlier form was authentity (1650s).
author (n.) Look up author at Dictionary.com
c. 1300, autor "father," from Old French auctor, acteor "author, originator, creator, instigator (12c., Modern French auteur), from Latin auctorem (nominative auctor) "enlarger, founder, master, leader," literally "one who causes to grow," agent noun from auctus, past participle of augere "to increase" (see augment). Meaning "one who sets forth written statements" is from late 14c. The -t- changed to -th- 16c. on mistaken assumption of Greek origin.
...[W]riting means revealing onesself to excess .... This is why one can never be alone enough when one writes, why even night is not night enough. ... I have often thought that the best mode of life for me would be to sit in the innermost room of a spacious locked cellar with my writing things and a lamp. Food would be brought and always put down far away from my room, outside the cellar's outermost door. The walk to my food, in my dressing gown, through the vaulted cellars, would be my only exercise. I would then return to my table, eat slowly and with deliberation, then start writing again at once. And how I would write! From what depths I would drag it up! [Franz Kafka]
author (v.) Look up author at Dictionary.com
1590s, from author (n.). Revived 1940s, chiefly U.S. Related: Authored; authoring.
authorial (adj.) Look up authorial at Dictionary.com
1796, from author (n.) + -al (1).
authorisation (n.) Look up authorisation at Dictionary.com
chiefly British English spelling of authorization (q.v.); for spelling, see -ize.
authorise (v.) Look up authorise at Dictionary.com
chiefly British English spelling of authorize (q.v.); for suffix, see -ize. Related: Authorised; authorising.
authoritarian (adj.) Look up authoritarian at Dictionary.com
1862, "favoring imposed order over freedom," from authority + -an. Compare authoritative, which originally had this meaning to itself. Noun in the sense of one advocating or practicing such governance is from 1859.
authoritarianism (n.) Look up authoritarianism at Dictionary.com
1883; see authoritarian + -ism. Early use mostly in communist jargon.
authoritative (adj.) Look up authoritative at Dictionary.com
c. 1600, "dictatorial" (a sense now restricted to authoritarian), from Medieval Latin authoritativus (see authority). Meaning "possessing authority" is recorded from 1650s; that of "proceeding from proper authority" is from 1809. Related: Authoritatively; authoritativeness.
authority (n.) Look up authority at Dictionary.com
early 13c., autorite "book or quotation that settles an argument," from Old French auctorité "authority, prestige, right, permission, dignity, gravity; the Scriptures" (12c.; Modern French autorité), from Latin auctoritatem (nominative auctoritas) "invention, advice, opinion, influence, command," from auctor "master, leader, author" (see author (n.)).

Usually spelled with a -c- in English till 16c., when it was dropped in imitation of the French. Meaning "power to enforce obedience" is from late 14c.; meaning "people in authority" is from 1610s. Authorities "those in charge, those with police powers" is recorded from mid-19c.
authorization (n.) Look up authorization at Dictionary.com
c. 1600, from authorize + -ation. Earlier form was auctorisation (late 15c.).
authorize (v.) Look up authorize at Dictionary.com
"give formal approval to," late 14c., autorisen, from Old French autoriser "authorize, give authority to" (12c.), from Medieval Latin auctorizare, from auctor (see author (n.)). Modern spelling from 16c. Related: Authorized; authorizing.
authorship (n.) Look up authorship at Dictionary.com
c. 1500, "the function of being a writer," from author (n.) + -ship. Meaning "literary origin" is attested from 1825.
autism (n.) Look up autism at Dictionary.com
1912, from German Autismus, coined 1912 by Swiss psychiatrist Paul Bleuler (1857-1939) from comb. form of Greek autos- "self" (see auto-) + -ismos suffix of action or of state. The notion is of "morbid self-absorption."
autistic (adj.) Look up autistic at Dictionary.com
1912 (Bleuler), from autism (q.v.). Noun meaning "person with autism" is recorded from 1968 (earlier in this sense was autist).
auto (n.) Look up auto at Dictionary.com
shortened form of automobile, 1899; same development yielded French auto.
auto- Look up auto- at Dictionary.com
word-forming element meaning "self, one's own, by oneself," from Greek auto- "self, one's own," combining form of autos "self, same," which is of unknown origin. Before a vowel, aut-; before an aspirate, auth-. In Greek also used as a prefix to proper names, as in automelinna "Melinna herself." The opposite prefix would be allo-.
auto-da-fe (n.) Look up auto-da-fe at Dictionary.com
1723, "sentence passed by the Inquisition" (plural autos-da-fé), from Portuguese auto-da-fé "judicial sentence, act of the faith," especially the public burning of a heretic, from Latin actus de fide, literally "act of faith." Although the Spanish Inquisition is better-known today, there also was one in Portugal.
auto-erotic (adj.) Look up auto-erotic at Dictionary.com
1898, coined by Havelock Ellis from auto- + erotic. Related: Auto-eroticism.
autobahn (n.) Look up autobahn at Dictionary.com
1937, German, from auto "motor car, automobile" + bahn "path, road," from Middle High German ban, bane "way, road," literally "strike" (as a swath cut through), from PIE *gwhen- "to strike, kill" (see bane).
autobiography (n.) Look up autobiography at Dictionary.com
1797, from auto- + biography. Related: Autobiographical.
autocade (n.) Look up autocade at Dictionary.com
1922, from auto(mobile) + ending from cavalcade.
autocar (n.) Look up autocar at Dictionary.com
1895, from auto- + car.
Which is it to be? We observe that the London Times has lent the weight of its authority to the word "autocar," which it now prints without the significant inverted commas but with a hyphen, "auto-car." We believe that the vocable originated with a journal called the Hardwareman, which succeeded in obtaining the powerful support of the Engineer for its offspring. As for ourselves, being linguistic purists, we do not care for hybrid constructions--"auto" is Greek, while "car" is Latin and Celtic. At the same time, such clumsy phrases as "horseless carriages," "mechanical road carriages," and "self-propelled vehicles" are not meeting with general favour. Why not therefore adopt the philogically sound "motor-car," which could be run into a single word, "motorcar"? ["The Electrical Engineer," Dec. 20, 1895]
autochthon (n.) Look up autochthon at Dictionary.com
1640s, "one sprung from the soil he inhabits" (plural autochthones), from Greek autokhthon "aborigines, natives," literally "sprung from the land itself," used of the Athenians and others who claimed descent from the Pelasgians, from auto- "self" (see auto-) + khthon "land, earth, soil" (see chthonic).
autochthonic (adj.) Look up autochthonic at Dictionary.com
1827, from autochthon + -ic.
autochthonous (adj.) Look up autochthonous at Dictionary.com
"native, indigenous," 1845, from autochthon + -ous.
autoclave (n.) Look up autoclave at Dictionary.com
1880, from French, literally "self-locking," from auto- "self" (see auto-) + Latin clavis "key" (see slot (n.2)).
autocracy (n.) Look up autocracy at Dictionary.com
1650s, "independent power, self-sustained power," from French autocratie, from Greek autokrateia "ruling by oneself," noun of state from autokrates (see autocrat). Meaning "absolute government, supreme political power" is recorded from 1855.
autocrat (n.) Look up autocrat at Dictionary.com
1803, from French autocrate, from Greek autokrates "ruling by oneself, absolute, autocratic," from autos- "self" (see auto-) + kratia "rule," from kratos "strength, power" (see -cracy). First used by Robert Southey, with reference to Napoleon. An earlier form was autocrator (1789), used in reference to the Russian Czars. Earliest form in English is the fem. autocratress (1762).
autocratic (adj.) Look up autocratic at Dictionary.com
1823, from French autocratique, from autocrate, from Greek autokrates (see autocrat). Earlier autocratoric (1670s) was directly from Greek autokratorikos. Autocratical is attested from 1801.
autodidact (n.) Look up autodidact at Dictionary.com
1746, from Greek autodidaktos "self-taught" (see autodidactic).
autodidactic (adj.) Look up autodidactic at Dictionary.com
"self-taught," 1838, from Greek autodidaktikos "self-taught," from autos "self" (see auto-) + didaktos "taught" (see didactic).
autogenous (adj.) Look up autogenous at Dictionary.com
"self-generated," 1846, earlier autogeneal (1650s), from Greek autogenes "self-produced," from autos "self" (see auto-) + genes "formation, creation" (see genus). Modern form and biological use of the word said to have been coined by English paleontologist Richard Owen (1804-1892).
autograph (n.) Look up autograph at Dictionary.com
"a person's signature," 1791, from Latin autographum, from Greek autographon, neuter of autographos "written with one's own hand," from autos- "self" (see auto-) + graphein "to write" (originally "to scratch;" see -graphy). Used earlier (1640s) to mean "author's own manuscript."
autograph (v.) Look up autograph at Dictionary.com
"to sign one's name," 1837, from autograph (n.). Related: Autographed; autographing. Earlier "to write with one's own hand" (1818).
autoharp (n.) Look up autoharp at Dictionary.com
1882, name on a patent taken out by Charles F. Zimmermann of Philadelphia, U.S.A., for an improved type of harp, an instrument considerably different from the modern autoharp, actually a chord zither, which was invented about the same time by K.A. Gütter of Markneukirchen, Germany, who called it a Volkszither.
autoimmune (adj.) Look up autoimmune at Dictionary.com
1952, from auto- + immune.
autolatry (n.) Look up autolatry at Dictionary.com
"self-worship," 1620s (in Latinate form autolatria), from auto- + -latry.
automaker (n.) Look up automaker at Dictionary.com
"manufacturer of automobiles," 1925, from auto + maker.
automat (n.) Look up automat at Dictionary.com
"automated cafeteria," 1903, probably from automatic.