nullify

synonyms nullify , negate , annul , abrogate , invalidate mean to deprive of effective or continued existence. nullify implies counteracting completely the force, effectiveness, or value of something <a penalty nullified the touchdown>. negate implies the destruction or canceling out of each of two things by the other <the arguments negate each other>. annul suggests making ineffective or nonexistent often by legal or official action <the treaty annuls all previous agreements>. abrogate is like annul but more definitely implies a legal or official act <a law to abrogate trading privileges>. invalidate implies making something powerless or unacceptable by declaration of its logical or moral or legal unsoundness <the court invalidated the statute>.