Nullify

v. t.

1.

To make void; to render invalid; to deprive of legal force or efficacy. [imp. & p. p. Nullified ; p. pr. & vb. n. Nullifying .] Such correspondence would at once nullify the conditions of the probationary system. - I. Taylor.

Verb	1.	nullify - declare invalid; "The contract was annulled"; "void a plea" Synonyms: annul, invalidate, void, quash, avoid
	2.	nullify - show to be invalid Synonyms: invalidate
	3.	nullify - make ineffective by counterbalancing the effect of; "Her optimism neutralizes his gloom"; "This action will negate the effect of my efforts" Synonyms: neutralize, neutralise, negate

abate, abjure, abrogate, absolve, annihilate, assert the contrary, belie, bring to naught, bring to nothing, buffer, cancel out, come to nothing, compensate, confine, contest, contradict, contravene, controvert, counter, counteract, counterbalance, countermand, counterorder, countervail, cross, declare a moratorium, deny, disaffirm, disallow, disannul, disavow, disclaim, disown, disprove, dispute, do away with, forswear, frustrate, gainsay, impugn, join issue upon, limit, make void, negate, negativate, negative, neutralize, not accept, not admit, offset, oppose, override, overrule, quash, recall, recant, refuse to admit, refute, renege, renounce, repeal, repudiate, rescind, restrict, retract, reverse, set aside, stultify, suspend, take back, take issue with, thwart, undo, vacate, vitiate, void, waive, wipe out, withdraw, write off