slash, scratch, scrap, toss (out), kill, black out, nix, retract, revoke, rescind, nullify, void, invalidate, undo, countermand, scuttle (a plan), overturn, negate, wipe out/clean, delete, cross out, veto, cancel (out), eliminate, reverse (a decision), abolish, contradict, override, do away with, obliterate (all traces of something)

shift, swing, compromise, switch, flip, adapt, alternate, alter, waver, oscillate, welsh, welch, deviate, vacillate, exchange, rethink, renege, amend, reverse, flip-flop, make a u-turn, flip (one's allegiance), reverse field, retract (an offer), switch around, toss aside, swap (positions), change (one's mind), vary (one's opinion), waffle, take turns, diverge, depart, stray, turn (away from), modify (one's stance), move between, break one's word/promise, make a one eighty

swing, question, adapt, fluctuate, waver, doubt, vacillate, change one's mind, revise, vary, flip-flop, shift (one's perspective), alter (one's view), adjust to (new information), modify (one's views), shilly-shally, lose one's convictions, distrust (one's perspective), warm to the idea

cast, sharpen, establish, slice through, define, highlight, illumine, illuminate, identify, redefine, take stock of, correct, specify, distinguish, discriminate, pinpoint, reiterate, clear up, tweak (an earlier theory), fine-tune (one's reasoning), hone (one's analysis), spell out (fine points), fill in (details), reorganize (one's priorities), demystify, couch, reach (a conclusion), expand on (particulars), elucidate, shed light on, explicate, make clear

invalidate, negate, contradict, minimize, repudiate, discredit, poke holes in, disprove, refute, explode (a myth), debunk, discount (as nonsense), prove false, shoot down, rebut