Synonyms of counteractive

2 Syllables
agin, naysaying, coner, checking
3 Syllables
remedy, remedies, countering, dissentient, medicant, counterstep
4 Syllables
negative, interfering, privative, antithetic, counteractant, opposite
5 Syllables
countermeasure, contradictory
6 Syllables
counterproductive, unaffirmative