The verb negate is to nullify, make something invalid or deny its existence.
Synonyms are invalidate, contradict, disaffirm or deny.
The word origins from Latin (1795) negātus, the past participle of negāre meaning “to say (with the negative of a conjoined clause), deny, withhold, say no”.
I did not expect the judge to negate the evidence.
His allergy was so strong that it negates the effect of the drug.
Just because the other one is better doesn’t give you the right to negate all the efforts that we have put into this project.