- 1nullify something to make something such as an agreement or order lose its legal force synonym invalidate Judges were unwilling to nullify government decisions.
- 2nullify something to make something lose its effect or power synonym negate An unhealthy diet will nullify the effects of training.
NAmE//ˈnʌləˌfaɪ//(formal)Verb Forms present simple I / you / we / they nullify
he / she / it nullifies
past simple nullified
-ing form nullifying
nullification noun [uncountable, countable]jump to other results