To mark out
erase, eradicate, cross off, cross out, wipe out, rub out, scratch out, scratch off, strike out, strike off, blank out, blot out, sponge out, rule out, wash out, wash off, black out, write off, efface, deface, delete, dele, cut, destroy, undo, expunge, obliterate, omit, drop, render invalid, stamp across, wipe the slate clean*; see also eliminate 1, remove 1.
Antonyms maintain*, sanction, renew.
To make void
annul, revoke, call off, recant, vacate, repudiate, nullify, negate, neutralize, ignore, invalidate, suppress, countermand, set aside, render null and void, declare null and void, declare invalid, rule out, refute, rescind, remove, repeal, counteract, recall, retract, reverse, abrogate, discharge, void, render void, put an end to, abort, drop, do away with, discontinue, withdraw, offset, counterpoise, balance out, render inert, deprive of force, overthrow, scratch*, scrap*, scrub*; see also abolish, discard, revoke.
Antonyms sustain*, approve*, uphold.