THESAURUS
Annul
abate, abolish, abrogate, abstract, annihilate, black out, blot out, bring to naught, bring to nothing, buffer, cancel, cancel out, come to nothing, counteract, counterbalance, countercheck, countermand, counterorder, delete, disannul, discharge, dispose of, dissolve, divorce, do away with, efface, eliminate, expunge, extinguish, frustrate, grant a divorce, grant an annulment, invalidate, make void, negate, negativate, negative, neutralize, nullify, obliterate, obtain a divorce, offset, outweigh, overbalance, override, overrule, part, put asunder, put away, quash, recall, recant, redress, remove, renege, repeal, rescind, retract, reverse, revoke, separate, set aside, split up, stultify, sue for divorce, suspend, thwart, undo, unmarry, untie the knot, vacate, vitiate, void, waive, wipe out, withdraw, write off
ROGET THESAURUS
Annul
Abrogation
VB
abrogate, annul, cancel, destroy, abolish, revoke, repeal, rescind, reverse, retract, recall, abolitionize, overrule, override, set aside, disannul, dissolve, quash, nullify, declare null and void, disestablish, disendow, deconsecrate, disclaim, ignore, repudiate, recant, divest oneself, break off, countermand, counter order, do away with, sweep away, brush away, throw overboard, throw to the dogs, scatter to the winds, cast behind, dismiss, discard, cast off, turn off, cast out, cast adrift, cast out of doors, cast aside, cast away, send off, send away, send packing, send about one's business, discharge, get rid of, bounce, fire, fire out, sack, cashier, break, oust, unseat, unsaddle, unthrone, dethrone, disenthrone, depose, uncrown, unfrock, strike off the roll, disbar, disbench, be abrogated, receive its quietus, walk the plank.