counteract

(verb) act in opposition to. Synonyms: antagonize, antagonise.

(verb) oppose or check by a counteraction. Synonyms: countercheck.

(verb) oppose and mitigate the effects of by contrary actions. Synonyms: countervail, neutralize, counterbalance. Example: "This will counteract the foolish actions of my colleagues."

(verb) destroy property or hinder normal operations. Synonyms: sabotage, undermine, countermine, subvert, weaken. Example: "The resistance sabotaged railroad operations during the war."