nullify

Verb	1.	nullify - declare invalid; "The contract was annulled"; "void a plea" annul, invalidate, void, quash, avoid strike down, cancel - declare null and void; make ineffective; "Cancel the election results"; "strike down a law" break - invalidate by judicial action; "The will was broken" stet - printing: cancel, as of a correction or deletion
	2.	nullify - show to be invalid invalidate negate, contradict - prove negative; show to be false
	3.	nullify - make ineffective by counterbalancing the effect of; "Her optimism neutralizes his gloom"; "This action will negate the effect of my efforts" neutralize, neutralise, negate weaken - lessen the strength of; "The fever weakened his body"

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