Online Etymology Dictionary

Antaeus: Libyan giant slain by Herakles, from Greek Antaios, literally "opposite, opposed to, hostile," from anta "over against, face to face," related to anti "opposite, against" (see ante).
antagonise (v.): chiefly British English spelling of antagonize; see -ize. Related: Antagonised; antagonising.
antagonism (n.): 1797, from French antagonisme or directly from late Greek antagonisma, noun of action from antagonizesthai "to struggle against" (see antagonist).
antagonist (n.): 1590s, from French antagoniste (16c.) or directly from Late Latin antagonista, from Greek antagonistes "competitor, opponent, rival," agent noun from antagonizesthai "to struggle against, oppose, be a rival," from anti- "against" (see anti-) + agonizesthai "to contend for a prize," from agon "contest" (see agony). Originally in battle or sport, extended 1620s to any sphere of human activity.
antagonistic (adj.): 1630s, from antagonist + -ic. Related: Antagonistical (1620s); antagonistically.
antagonize (v.): 1630s, "to compete with," from Greek antagonizesthai "to struggle against, oppose, be a rival" (see antagonist). Meaning "to struggle against continuously" is recorded from 1742. Related: Antagonized; antagonizing.
antalgic (adj.): 1775, from Greek ant-, form of anti- used before vowels (see anti-), + algos "pain" (see -algia). As a noun, recorded from 1753.
antaphrodisiac: 1742 (adj.), 1753 (n.), "used against venereal disease;" see anti- + aphrodisiac.
antarchism (n.): "opposition to all social government or control of individuals by law," 1845, from antarchy + -ism. Related: Antarchist.
antarchy (n.): "opposition to government," 1650s, from anti- + Greek -arkhia (see -archy). Related: Antarchic.
antarctic (adj.): late 14c., antartyk "opposite to the north pole" (adj.), also (with capital A) "region around the South pole" (n.), from Old French antartique, from Medieval Latin antarcticus, from Greek antarktikos "opposite the north," from anti- "opposite" (see anti-) + arktikos "arctic" (see arctic). The first -c- sound ceased to be pronounced in Medieval Latin and was dropped in Old French. Modern English spelling, which restores it, dates from 17c.
Antarctica: continent name attributed to Scottish cartographer John George Bartholomew (1860-1920), who used it on a map published 1887. From antarctic (q.v.). Hypothetical southern continents had been imagined since antiquity; first sighting of Antarctica by Europeans probably was 1820 (Lazarev and Bellingshausen). Also compare Antipodes.
Antares: bright star in Scorpio, from Greek Antares, from anti Ares "rival of Mars," in reference to its red color, which resembles that of Mars. See anti- + Ares.
ante: 1838 (n.), 1846 (v.), American English poker slang, apparently from Latin ante "before," from PIE *anti- "facing opposite, against," with derivatives meaning "in front of, before; end" (source also of Sanskrit antah "end, border, boundary," Hittite hanti "opposite," Greek anta, anten "opposite," anti "over against, opposite, before;" Old Lithuanian anta "on to;" Gothic anda "along;" Old English and- "against;" German ent- "along, against"), from root *ant- "front, forehead."
ante meridiem: 1560s, Latin, literally "before noon," from ante (see ante) + accusative of meridies "midday, noon" (see meridian).
ante-: word-forming element meaning "before, in front of; previous, existing beforehand; introductory to," from Latin ante (prep. and adv.) "before, in front of, opposite," used in combinations, from PIE *anti "facing opposite, near, in front of, before" (see ante).
anteater (n.): also ant-eater, 1764, in reference to the South American species; 1868 of the Australian echidna; from ant + agent noun from eat (v.).
antebellum (adj.): also ante-bellum, from Latin phrase ante bellum, literally "before the war;" see ante- + bellicose. In U.S., usually in reference to the American Civil War (1861-65); first attested in a June 14, 1862, entry in Mary Chesnut's diary.
antecede (v.): early 15c., from Latin antecedere "to go before" (see antecedent). Related: Anteceded; anteceding.
antecedent: late 14c. (n. and adj.), from Old French antecedent (14c.) or directly from Latin antecedentem (nominative antecedens), present participle of antecedere "go before, precede," from ante- "before" (see ante) + cedere "to yield" (see cede). Used as a noun in Latin philosophical writings.
antechamber (n.): 1650s, from French antichambre (16c.), on analogy of Italian anticamera (see ante and chamber).
antedate (v.): 1580s, earlier as noun meaning "a backdating, false early date attached to a document or event" (1570s); from Latin ante "before" (see ante) + date (v.1). Related: Antedated; antedating.
antediluvian (adj.): "before Noah's flood," 1640s, formed from Latin ante- "before" (see ante) + diluvium "a flood" (see deluge (n.)). Coined by English physician Sir Thomas Browne (1605-1682). As a noun meaning "person who lived before the Flood," from 1680s.
antelope (n.): early 15c., from Old French antelop, from Medieval Latin ant(h)alopus (11c.), from Greek antholops (attested in Eusebius of Antioch, c.336 C.E.), a fabulous animal haunting the banks of the Euphrates, very savage, hard to catch and having long saw-like horns capable of cutting down trees. Original sense and language unknown (it looks like Greek "flower-eye," as if from anthos + ops, but that may be a result of Greek folk etymology). A heraldic animal, also known in Medieval Latin as talopus and calopus, the name was applied c. 1600 to a living type of deer-like mammal. In the western U.S., it is used in reference to the pronghorn.
antemundane (adj.): "existing or happening before the creation of the world," 1731; see ante- + mundane.
antenatal (adj.): "before birth," 1798, from Latin ante "before" (see ante) + natal.
antenna (n.): 1640s, "feeler or horn of an insect," from Latin antenna "sail yard," the long yard that sticks up on some sails, which is of unknown origin, perhaps from PIE root *temp- "to stretch, extend." In the etymological sense, it is a loan-translation of Aristotle's Greek keraiai "horns" (of insects). Modern use in radio, etc., for "aerial wire" is from 1902. Adjectival forms are antennal (1834), antennary (1836), antennular (1858).
antennae (n.): Latinate plural of antenna; see -ae.
antennas (n.): nativized plural of antenna; see -ae.
antenuptial (adj.): "prior to marriage," 1818, originally of children's births; see ante- + nuptial.
antepartum (adj.): 1908, from Latin phrase ante partum "before birth" (see postpartum).
antepenult (n.): 1610s; see antepenultimate.
antepenultimate (adj.): "the last but two," 1730, from antepenult (n.), 1610s, abbreviation of Latin antepaenultima (syllaba), fem. of antepaenultimus, from ante "before" (see ante) + paenultima, from paen "almost" + ultima "last" (see ultimate).
anterior (adj.): 1610s, Latin, literally "former," comparative of ante "before" (see ante). Related: Anteriority.
anteroom (n.): also ante-room, 1762, literally "a room in front;" after French antichambre, Italian anticamera, from Latin ante "before" (see ante) + camera (see chamber).
anthem (n.): Old English ontemn, antefn, "a composition (in prose or verse) sung antiphonally," from Late Latin antefana, from Greek antiphona "verse response" (see antiphon). Sense evolved to "a composition set to sacred music" (late 14c.), then "song of praise or gladness" (1590s). Used in reference to the English national song (technically, as OED points out, a hymn) and extended to those of other nations. Modern spelling is from late 16c., perhaps an attempt to make the word look more Greek.
anthemic (adj.): of music, "felt to resemble an anthem," 1841, from anthem + -ic. In reference to a type of acid, 1859, so called because isolated from dog-fennel (Anthemis arvensis).
anther (n.): 1550s, "medical extract of flowers," from French anthère, from Modern Latin anthera "a medicine extracted from a flower," from Greek anthera, fem. of antheros "flowery, blooming," from anthos "flower," from PIE root *andh- "to bloom" (source also of Sanskrit andhas "herb," Armenian and "field," Middle Irish ainder "young girl," Welsh anner "young cow"). Main modern sense attested by 1791.
anthesis (n.): "full bloom," 1835, from Greek anthesis, noun of action from antheein "to blossom," from anthos "flower," (see anther).
anthill (n.): late 13c., from ant + hill (n.).
anthologize (v.): 1889; see anthology + -ize. Related: Anthologized; anthologizing.
anthology (n.): 1630s, "collection of poetry," from Latin anthologia, from Greek anthologia "collection of small poems and epigrams by several authors," literally "flower-gathering," from anthos "a flower" (see anther) + logia "collection, collecting," from legein "gather" (see lecture (n.)). Modern sense (which emerged in Late Greek) is metaphoric, "flowers" of verse, small poems by various writers gathered together.
Anthony: masc. proper name, from Latin Antonius, name of a Roman gens (with excrescent -h- probably suggested by many Greek loan words beginning anth-, such as anthros "flower," anthropos "man"); St. Anthony (4c.), Egyptian hermit, patron saint of swineherds, to whom one of each litter was usually vowed, hence Anthony for "smallest pig of the litter (1660s; in condensed form tantony pig from 1590s). St. Anthony's Fire (1520s), popular name for erysipelas, is said to be so called from the tradition that those who sought his intercession recovered from that distemper during a fatal epidemic in 1089.
anthracite (n.): "non-bituminous coal," 1812, earlier (c. 1600) a type of ruby-like gem described by Pliny, from Latin anthracites "bloodstone, semi-precious gem," from Greek anthrakites "coal-like," from anthrax (genitive anthrakos) "live coal" (see anthrax). Related: Anthractic (adj.).
anthrax (n.): late 14c., "any severe boil or carbuncle," from Latin, from Greek anthrax "charcoal, live coal," also "carbuncle," which is of unknown origin. Specific sense of the malignant disease in sheep and cattle (and occasionally humans) is from 1876.
anthro-: see anthropo-.
anthropic (adj.): "pertaining to man," 1836, from Greek anthropikos "human," from anthropos "male human being, man" (see anthropo-). Related: Anthropical (1804).
anthropo-: before a vowel, anthrop-, word-forming element meaning "pertaining to man or human beings," from Greek anthropos "man, human being" (sometimes also including women) from Attic andra (genitive andros), from Greek aner "man" (as opposed to a woman, a god, or a boy), from PIE *ner- (2) "man," also "vigorous, vital, strong" (source also of Sanskrit nar-, Armenian ayr, Welsh ner).

Anthropos sometimes is explained as a compound of aner and ops (genitive opos) "eye, face;" so literally "he who has the face of a man." The change of -d- to -th- is difficult to explain; perhaps it is from some lost dialectal variant, or the mistaken belief that there was an aspiration sign over the vowel in the second element (as though *-dhropo-), which mistake might have come about by influence of common verbs such as horao "to see."
anthropocentric (adj.): "regarding man as the center," 1855, from anthropo- + -centric. Related: Anthropocentrically.
anthropocentrism (n.): 1897; see anthropocentric + -ism.