coun·ter·act 
/ˌkaʊntɚˈækt/ verb
coun·ter·acts; coun·ter·act·ed; coun·ter·act·ing /ˌkaʊntɚˈækt/ verb [+ obj] : act against (something) : to cause (something) to have less of an effect or to have no effect at all
▪ The drug will counteract the poison. ▪ The new fees will counteract [=offset] state cuts in the school's budget.
▪ The drug will counteract the poison. ▪ The new fees will counteract [=offset] state cuts in the school's budget.
