nullify Synonyms

annul cancel invalidate avoid quash revoke neutralize repeal negate neutralise void recall extirpate overturn overthrow foil frustrate overrule override halt offset nullifying invalidating invalidated disacknowledge recant repudiate declare null and void bring to naught cancel out to abrogate wipe out set aside withdraw abolish vitiate veto vacate undo reverse retract rescind declare invalid extinguish countermand counterbalance counteract counter contravene compense