counteract
/ˌkauntəˈrækt; ˌkaʊntɚ`ækt/ v[Tn]
act against and reduce the force or effect of (sth) 对抗; 抵消
counteract (the effects of) a poison, sb's bad influence, etc 消解毒性（的作用）、 清除某人的不良影响
We must counteract extremism in the party. 我们应该抵制党内的极端主义.