| Invalidate (v. t.) To weaken or lessen; to destroy the authority of; to render useless; as, to invalidate an agreement or argument. Thesaurus Entries abate, abolish, abrogate, annihilate, annul, belie, blow sky-high, blow up, bring to naught, bring to nothing, buffer, cancel, cancel out, come to nothing, counterbalance, countermand, counterorder, deflate, disannul, disconfirm, discredit, disprove, disqualify, do away with, explode, expose, frustrate, make void, negate, negativate, negative, neutralize, nullify, offset, override, overrule, prove the contrary, puncture, quash, recall, recant, renege, repeal, rescind, retract, reverse, revoke, set aside, show up, stultify, suspend, thwart, undercut, undo, unfit, vacate, vitiate, void, waive, withdraw, write off |