VERB
使失去法律效力;废除;取消
To nullify a legal decision or procedure means to declare that it is not legally valid.
例句
He used his broad executive powers to nullify decisions by local governments...
他利用自己适用范围广泛的行政权力废止当地政府所作的决定。
It is worth remembering that previous wills are nullified automatically upon marriage.
要记住的是,一旦结婚,原遗嘱自动失效。