v.
Pronunciation: ˌ kau ̇ n-t ə r- ' akt
Function: transitive verb
Date: 1655
: to make ineffective or restrain or neutralize the usually ill effects of by means of an opposite force, action, or influence <a drug used to counteract fatigue>
– coun · ter · ac · tion \ - ' ak-sh ə n \ noun
– coun · ter · ac · tive \ - ' ak-tiv \ adjective