The Collaborative International Dictionary of English v.0.48:

Anti \An"ti\ [Gr. 'anti` against. See Ante.]
   A prefix meaning against, opposite or opposed to, contrary,
   or in place of; -- used in composition in many English words.
   It is often shortened to ant-; as, antacid, antarctic.
   [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

64 Moby Thesaurus words for "anti":
   adversary, adversative, adverse, adversive, alien, antagonistic,
   antipathetic, antithetic, antonymous, at cross-purposes, balancing,
   clashing, compensating, competitive, con, conflicting, confronting,
   contradictory, contradistinct, contrapositive, contrarious,
   contrary, contrasted, converse, counter, counterbalancing,
   counterpoised, countervailing, cross, dead against, disaccordant,
   discordant, discrepant, dissentient, enemy, eyeball to eyeball,
   fractious, hostile, inconsistent, inimical, inverse, negative,
   noncooperative, obstinate, obverse, opponent, opposed, opposing,
   opposite, oppositional, oppositive, oppugnant, overthwart,
   perverse, recalcitrant, refractory, repugnant, reverse, rival,
   squared off, uncooperative, unfavorable, unfriendly,
   unpropitious