antivenin n.

word-forming element of Greek origin meaning "against, opposed to, opposite of, instead," shortened to ant- before vowels and -h-, from Old French anti- and directly from Latin anti-, from Greek anti (prep.) "over, against, opposite; instead, in the place of; as good as; at the price of; for the sake of; compared with; in opposition to; in return; counter-," from PIE *anti "against," also "in front of, before" (from root *ant- "front, forehead," with derivatives meaning "in front of, before"), which became anti- in Italian (hence antipasto) and French.

It is cognate with Sanskrit anti "over, against," and Old English and- (the first element in answer). A common compounding element in Greek, in some combinations it became anth- for euphonic reasons. It appears in some words in Middle English but was not commonly used in English word formations until modern times. In a few English words (anticipate, antique) it represents Latin ante.

In noun compounds where it has the sense of "opposed to, opposite" (Antichrist, anti-communist) the accent remains on the anti-; in adjectives where it retains its old prepositional sense "against, opposed to," the accent remains on the other element (anti-Christian, anti-slavery).

mid-13c., venim, venym, "poison secreted by some animals and transferred by biting," from Anglo-French and Old French venim, venin "poison; malice," from Vulgar Latin *venimen (source also of Italian veleno, Spanish veneno), from Latin venenum "poison," earlier (pre-classical) "drug, medical potion," also "charm, seduction," probably originally "love potion," from PIE *wenes-no-, from root *wen- (1) "to desire, strive for." Variously deformed in post-Latin languages, apparently by dissimilation. Modern spelling in English from late 14c. The meaning "bitter, virulent feeling or language" is first recorded c. 1300.

word-forming element in chemistry, usually indicating a neutral substance, antibiotic, vitamin, or hormone; a modification and specialized use of -ine (2).