counteract Meaning, Definition & Usage

  1. verb act in opposition to
    antagonize; antagonise.
  2. verb oppose or check by a counteraction
    countercheck.
  3. verb oppose and mitigate the effects of by contrary actions
    countervail; counterbalance; neutralize.
    • This will counteract the foolish actions of my colleagues
  4. verb destroy property or hinder normal operations
    countermine; subvert; sabotage; undermine; weaken.
    • The Resistance sabotaged railroad operations during the war

WordNet

Coun`ter*act" transitive verb
Wordforms
imperfect & past participle Counteracted; present participle & verbal noun Counteracting
Definitions
  1. To act in opposition to; to hinder, defeat, or frustrate, by contrary agency or influence; as, to counteract the effect of medicines; to counteract good advice.

Webster 1913