(nullifies, ~ing, nullified)
1.
To ~ a legal decision or procedure means to declare that it is not legally valid. (FORMAL)
He used his broad executive powers to ~ decisions by local governments...
It is worth remembering that previous wills are nullified automatically upon marriage.
= invalidate
VERB: V n, V n
2.
To ~ something means to make it have no effect. (FORMAL)
He may be able to ~ that disadvantage by offering a wider variety of produce...
= negate
VERB: V n