nullify
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/ˈnʌlɪfaɪ/
🇬🇧
/ˈnʌlɪfaɪ/
To cancel or make something invalid, especially by legal means.
The court nullified the contract because it was signed under false pretenses.
To counteract or cancel out the effects of something.
Eating junk food can nullify the benefits of your workout.