adversary, adversative, adverse, alien, antagonistic, anti, antipathetic, antithetic, clashing, competing, con, conflicting, contradictory, contrary, counter, cross, cutthroat, disaccordant, dissentient, emulous, enemy, fractious, hostile, in competition, in rivalry, inimical, negative, noncooperative, obstinate, opponent, opposed, opposing, opposite, oppositional, oppositive, oppugnant, overthwart, perverse, recalcitrant, refractory, repugnant, rival, rivaling, uncooperative, unfavorable, unfriendly, unpropitious, vying