WordNet (r) 3.0 (2006):
countermeasure n 1: an action taken to offset another actionMoby Thesaurus II by Grady Ward, 1.0:
18 Moby Thesaurus words for "countermeasure": antidote, backfire, comeback, corrective, counteractant, counteractive, counteragent, counterattack, counterblast, counterblow, counterfire, counterinsurgency, counterrevolution, counterstep, counterstroke, cure, defense, retort