Same word as nigging:

abate, abolish, abrogate, annihilate, annul, ax, blue pencil, bring to naught, call all bets off, compensate, confine, counteract, counterbalance, countervail, disannul, forget it, invalidate, kill, limit, negate, neutralize, nig, offset, quash, render null and void, renege, renig, repeal, rescind, restrict, scratch, scrub, squash, stamp out, take out, torpedo, trash, undo, veto, vitiate, void, wash out, wipe out, zap