This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

v. To make null; invalidate.

v. To counteract the force or effectiveness of.

v. to make legally invalid.

v. to prevent from happening

v. To make void; to render invalid; to deprive of legal force or efficacy.

To annul; make void; render invalid; deprive of force or efficacy.

Synonyms Annul, Annihilate, etc. See neutralize.

v. show to be invalid

v. declare invalid

v. make ineffective by counterbalancing the effect of

"Curb asks a judge to force McGraw to turn in new material for a fifth album, bar him from signing with another label and nullify a 2001 agreement that eliminated a sixth record from McGraw's contract."

create   

nullified    nullifies    nullifying   

negate    contradict    weaken   

invalidate    annihilate    destroy    counteract   

nullified   

revoke    repeal    abrogate    cancel    annul    abolish    invalidate    negative    negate    null