adversative, adverse, alien, antagonist, antagonistic, anti, antipathetic, antithetic, archenemy, assailant, bitter enemy, clashing, combatant, competitive, competitor, con, conflicting, contradictory, contrary, counter, cross, devil, disaccordant, dissentient, enemy, foe, foeman, fractious, hostile, inimical, negative, noncooperative, obstinate, open enemy, opponent, opposed, opposing, opposing party, opposite, opposite camp, oppositional, oppositive, oppugnant, overthwart, perverse, public enemy, recalcitrant, refractory, repugnant, rival, sworn enemy, the loyal opposition, the opposition, uncooperative, unfavorable, unfriendly, unpropitious