Online Etymology Dictionary

availment (n.): 1690s, from avail + -ment.
avalanche (n.): 1763, from French avalanche (17c.), from Romansch (Swiss) avalantze "descent," altered (by metathesis of -l- and -v-, probably influenced by Old French avaler "to descend, go down") from Savoy dialect lavantse, from Provençal lavanca "avalanche," perhaps from a pre-Latin Alpine language (the suffix -anca suggests Ligurian). As a verb, from 1872.
avant: French, literally "before," in various terms borrowed into English, corresponding to Italian avanti, both from Latin abante, a compound of ab "from" (see ab-) and ante "before" (see ante).
avant-garde (n.): (also avant garde, avantgarde); French, literally "advance guard" (see avant + guard (n.)). Used in English 15c.-18c. in a literal, military sense; borrowed again 1910 as an artistic term for "pioneers or innovators of a particular period." Also used around the same time in communist and anarchist publications. As an adjective, by 1925.
The avant-garde générale, avant-garde stratégique, or avant-garde d'armée is a strong force (one, two, or three army corps) pushed out a day's march to the front, immediately behind the cavalry screen. Its mission is, vigorously to engage the enemy wherever he is found, and, by binding him, to ensure liberty of action in time and space for the main army. ["Sadowa," Gen. Henri Bonnal, transl. C.F. Atkinson, 1907]
avarice (n.): c.1300, from Old French avarice "greed, covetousness" (12c.), from Latin avaritia "greed," from avarus "greedy," adjectival form of avere "crave, long for."
avaricious (adj.): late 15c., from Old French avaricios "greedy, covetous" (Modern French avaricieux), from avarice (see avarice). An Old English word for it was feoh-georn. Related: Avariciously; avariciousness.
avast: 1680s, a nautical interjection, "hold! stop!" probably worn down from Dutch houd vast "hold fast."
AVAST. -- The order to stop, or pause, in any exercise or operation; as Avast heaving -- that is to say, desist, or stop, from drawing in the cable or hawser, by means of the capstan &c. [George Biddlecombe, "The Art of Rigging," 1848]
avatar (n.): 1784, "descent of a Hindu deity," from Sanskrit avatarana "descent" (of a deity to the earth in incarnate form), from ava- "down" + base of tarati "(he) crosses over," from PIE root *tere- "to cross over" (see through). In computer use, it seems to trace to the novel "Snowcrash" (1992) by Neal Stephenson.
avaunt: interjection, late 15c., "begone," literally "move on," from Middle French avant "forward!" (see avant).
ave: "hail," also "farewell," early 13c. (in reference to the Ave Maria), from Latin ave, second person singular imperative of avere "to be or fare well."
Ave Maria: modified form of the angelic salutation to the Virgin (Luke i:28) used as a devotional recitation, early 13c., from the opening words ("Ave [Maria] gratia plena").
avenge (v.): late 14c., from Anglo-French avenger, Old French avengier, from a- "to" (see ad-) + vengier "take revenge" (Modern French venger), from Latin vindicare "to claim, avenge, punish" (see vindicate). Related: Avenged; avenging.
avenger (n.): 1530s, agent noun from avenge (v.). Spenser (1596) has avengeress but no mention of Mrs. Peel.
avenue (n.): c.1600, "a way of approach" (originally a military word), from Middle French avenue "way of access," from Old French avenue "act of approaching, arrival," noun use of fem. of avenu, past participle of avenir "to come to, arrive," from Latin advenire "to come to," from ad- "to" (see ad-) + venire "to come" (see venue). Meaning shifted to "a way of approach to a country-house," usually bordered by trees, hence, "a broad, tree-lined roadway" (1650s), then to "wide, main street" (by 1846, especially in U.S.).
aver (v.): late 14c., from Old French averer "verify," from Vulgar Latin *adverare "make true, prove to be true," from Latin ad- "to" (see ad-) + verus "true" (see very). Related: Averred; averring.
average (n.): late 15c., "financial loss incurred through damage to goods in transit," from French avarie "damage to ship," and Italian avaria; a word from 12c. Mediterranean maritime trade (cf. Spanish averia; other Germanic forms, Dutch avarij, German haferei, etc., also are from Romanic languages), of uncertain origin. Sometimes traced to Arabic 'arwariya "damaged merchandise," but this might as easily be a borrowing of the word from the Franks. Meaning shifted to "equal sharing of such loss by the interested parties." Transferred sense of "statement of a medial estimate" is first recorded 1735. The mathematical extension is from 1755.
average (adj.): 1770; see average (n.).
average (v.): 1769, from average (n.). Related: Averaged; averaging.
Averroes: Latinization of name of Ibn Rushd (1126-1198) Arab philosopher and physician of Spain and Morocco.
averse (adj.): mid-15c., "turned away in mind or feeling," from Old French avers and directly from Latin aversus "turned away, turned back," past participle of avertere (see avert). Originally and usually in English in the mental sense, while avert is used in a physical sense.
aversion (n.): "a turning away from," 1590s; figurative sense of "mental attitude of repugnance" is from 1650s, from Middle French aversion and directly from Latin aversionem (nominative aversio), noun of action from past participle stem of aversus "turned away, backwards, behind, hostile," itself past participle of avertere (see avert). Earlier in the literal sense of "a turning away from" (1590s). Aversion therapy in psychology is from 1950.
avert (v.): c.1400, from Old French avertir (12c.), "turn, direct; avert; make aware," from Vulgar Latin *advertire, from Latin avertere "to turn away, to drive away," from ab- "from, away" (see ab-) + vertere "to turn" (see versus). Related: Averted; averting.
Avestan: Eastern Iranian language that survived in sacred texts centuries after it went extinct, from Persian Avesta "sacred books of the Parsees," earlier Avistak, literally "books."
avian (adj.): "pertaining to birds," 1870, from Latin avis "bird" (see aviary) + -an.
aviary (n.): 1570s, from Latin aviarium "place in which birds are kept," neuter of aviarius "of birds," from avis "bird," from PIE *awi- "bird" (cf. Sanskrit vih, Avestan vish "bird," Greek aietos "eagle").
aviation (n.): 1866, from French aviation, noun of action from stem of Latin avis "bird" (see aviary). Coined 1863 by French aviation pioneer Guillaume Joseph Gabriel de La Landelle (1812-1886) in "Aviation ou Navigation aérienne."
aviator (n.): "aircraft pilot," 1887, from French aviateur, from Latin avis (see aviary) + -ateur. Also used c.1891 in a sense of "aircraft." Feminine form aviatrix is from 1927; earlier aviatrice (1910), aviatress (1911).
Avicenna: Latinization of name of Ibn Sina (980-1037), Persian philosopher and physician. Full name Abū ‘Alī al-Husayn ibn ‘Abd Allāh ibn Sīnā al-Balkhī.
aviculture (n.): 1876, from French aviculture, from Latin avis "bird" (see aviary) + Latin cultura "cultivation" (see culture).
avid (adj.): 1769, from French avide (15c.), from Latin avidus "longing eagerly, desirous, greedy," from avere "to desire eagerly." Also in part a back-formation from avidity. Related: Avidly.
avidity (n.): mid-15c., "eagerness, zeal," from Old French avidite "avidity, greed," from Latin aviditatem (nominative aviditas) "eagerness, avidity," noun of quality from avidus (see avid).
avionics (n.): 1949, from aviation + electronics.
Avis: U.S. car rental company, according to company history, founded 1946 at Willow Run Airport in Detroit by Warren Avis.
avocado (n.): 1763, from Spanish avocado, altered (by folk etymology influence of earlier Spanish avocado "lawyer," from same Latin source as advocate (n.)) from earlier aguacate, from Nahuatl ahuakatl "avocado, testicle." So called for its shape. As a color, first attested 1945. The English corruption alligator (pear) is 1763, from Mexican Spanish alvacata, alligato.
avocation (n.): 1520s, "a calling away from one's occupation," from Latin avocationem (nominative avocatio) "a calling away, distraction, diversion," noun of action from past participle stem of avocare, from ab- "off, away from" (see ab-) + vocare "to call" (see voice (n.)).
avoid (v.): c.1300, from Anglo-French avoider "to clear out, withdraw (oneself)," partially anglicized from Old French esvuidier "to empty out," from es- "out" (see ex-) + vuidier "to be empty," from voide "empty, vast, wide, hollow, waste" (see void (adj.)). Originally a law term; modern sense of "have nothing to do with" also was in Middle English and corresponds to Old French eviter with which it was perhaps confused. Meaning "escape, evade" first attested 1520s. Related: Avoided; avoiding.
avoidable (adj.): 1630s, from avoid + -able. Related: Avoidably.
avoidance (n.): late 14c., "action of emptying," from avoid + -ance. Sense of "action of dodging or shunning" is recorded from early 15c.; it also meant "action of making legally invalid," 1620s; "becoming vacant" (of an office, etc.), mid-15c.
avoirdupois (n.): 1650s, misspelling of Middle English avoir-de-peise (c.1300), from Old French avoir de pois "goods of weight," from aveir "property, goods" (noun use of aveir "have") + peis "weight," from Latin pensum, neuter of pendere "to weigh" (see pendant (n.)). After late 15c., the standard system of weights used in England for all goods except precious metals, precious stones, and medicine.
Avon: river in southwestern England, from Celtic abona "river" (see afanc).
avouch (v.): late 15c., from Middle French avochier "call upon as authority," in Old French "call (to court), advocate, plead (a case)," from Latin advocare "call to" as a witness (see advocate).
Avouch, which is no longer in common use, means guarantee, solemnly aver, prove by assertion, maintain the truth or existence of, vouch for .... Avow means own publicly to, make no secret of, not shrink from admitting, acknowledge one's responsibility for .... Vouch is now common only in the phrase vouch for, which has taken the place of avouch in ordinary use, & means pledge one's word for .... [Fowler]
Related: Avouched; avouching.
avow (v.): early 13c., from Anglo-French avouer, Old French avoer "acknowledge, accept, recognize," especially as a protector (Modern French avouer), from Latin advocare (see advocate). A synonym of avouch (q.v.), which tends to contain the more technical, legal aspect of the word. Related: Avowed; avowing.
avowal (n.): 1727, from avow + -al (2).
avuncular (adj.): 1789, from Latin avunculus "maternal uncle," diminutive of avus (see uncle) + -ar. Used humorously for "of a pawnbroker" (uncle was slang for "pawnbroker" from c.1600 through 19c.).
My only good suit is at present under the avuncular protection. ["Fraser's Magazine," 1832]
aw: expresion of mild disappointment, sympathy, etc., first recorded in this form by 1888.
AWACS (n.): 1966, initialism for "Airborne Warning and Control Systems."
await (v.): early 13c., awaiten, from Old North French awaitier (Old French agaitier) "to lie in wait for, watch, observe," from a- "to" (see ad-) + waitier "to watch" (see wait (v.)). Originally especially with a hostile sense. Related: Awaited; awaiting.
awake (v.): a merger of two Middle English verbs: 1. awaken, from Old English awæcnan (earlier onwæcnan; strong, past tense awoc, past participle awacen) "to awake, arise, originate," from a "on" + wacan "to arise, become awake" (see wake (v.)); and 2. awakien, from Old English awacian (weak, past participle awacode) "to awaken, revive; arise; originate, spring from," from a "on" (see a (2)) + wacian "to be awake, remain awake, watch" (see watch (v.)).

Both originally were intransitive only; the transitive sense being expressed by Middle English awecchen (from Old English aweccan) until later Middle English. In Modern English, the tendency has been to restrict the strong past tense and past participle (awoke, awoken) to the original intransitive sense and the weak inflection (awakened) to the transitive, but this never has been complete (see wake (v.); also cf. awaken).
awake (adj.): "not asleep," c.1300, shortened from awaken, past participle of Old English awæcnan (see awaken).
awaken (v.): Old English awæcnan (intransitive), "to spring into being, arise, originate," also, less often, "to wake up;" earlier onwæcnan, from a- (1) "on" + wæcnan (see waken). Transitive meaning "to rouse from sleep" is recorded from 1510s; figurative sense of "to stir up, rouse to activity" is from c.1600.

Originally strong declension (past tense awoc, past participle awacen), already in Old English it was confused with awake (v.) and a weak past tense awæcnede (modern awakened) emerged and has since become the accepted form, with awoke and awoken transferred to awake. Subtle shades of distinction determine the use of awake or awaken in modern English. Related: Awakening.