mindmap root((废除)) nullify implies counteracting completely the force, effectiveness, or value of something: his critical insights are ~ied by tiresome puns. negate implies the destruction or canceling out of one of two mutually exclusive things by the other: a relationship ~d by petty jealousies. annul suggests a neutralizing or a making ineffective or nonexistent often by legal or official action: the treaty ~s all previous agreements. abrogate is like annul, but more definitely implies a legal or official purposeful act: a law that would ~ certain diplomatic privileges. invalidate implies a making of something powerless or unacceptable by a declaration of its logical or moral or legal unsoundness: the absence of witnesses ~s the will.