nullify

As verbs the difference between mitigate and nullify

is that mitigate is to reduce, lessen, or decrease while nullify is to make legally invalid.

As verbs the difference between counteract and nullify

is that counteract is to act in opposition to; thwart; to hinder, defeat, or frustrate, by contrary agency or influence; as, to counteract the effect of medicines; to counteract good advice while nullify is to make legally invalid.

As verbs the difference between nullify and disinvent

is that nullify is (legal) to make legally invalid while disinvent is to nullify a previous invention.