THESAURUS
waver
alternate, back and fill, beat, beating, bicker, blench, bob, bobble, boggle, careen, change, coggle, dance, dangle, demur, dither, ebb and flow, equivocate, falter, fight shy of, flap, flick, flicker, flinch, flip, flit, flitter, flop, flounder, fluctuate, flutter, go pitapat, go through phases, gutter, halt, hang back, hang off, have qualms, hem and haw, hesitate, hold off, librate, lurch, make bones about, nutate, oscillate, palpitate, palpitation, palter, pause, pendulate, pitapat, pitch, pitter-patter, play, pull back, pulse, quail, quiver, recoil, reel, resonate, ring the changes, rock, roll, scruple, seesaw, shake, shift, shilly-shally, shrink, shuffle, shy, shy at, slat, splutter, sputter, stagger, stick at, stickle, strain, swag, sway, swing, swinging, teeter, teeter-totter, tergiversate, throb, toss, totter, trim, turn, vacillate, vary, vibrate, wag, waggle, wave, wax and wane, whiffle, wince, wobble
ROGET THESAURUS
waver
Tergiversation
VB
change one's mind, change one's intention, change one's purpose, change one's note, abjure, renounce, withdraw from,
waver, vacillate, wheel round, turn round, veer round, turn a pirouette, go over from one side to another, pass from one side to another, change from one side to another, skip from one side to another, go to the rightabout, box the compass, shift one's ground, go upon another tack, apostatize, change sides, go over, rat, recant, retract, revoke, rescind, recall, forswear, unsay, come over, come round to an opinion, crawfish, crawl, draw in one's horns, eat one's words, eat the leek, swallow the leek, swerve, flinch, back out of, retrace one's steps, think better of it, come back return to one's first love, turn over a new leaf, trim, shuffle, play fast and loose, blow hot and cold, coquet, be on the fence, straddle, bold with the hare but run with the hounds, nager entre deux eaux, wait to see how the cat jumps, wait to see how the wind blows.
Changeableness
VB
fluctuate, vary,
waver, flounder, flicker, flitter, flit, flutter, shift, shuffle, shake, totter, tremble, vacillate, wamble, turn and turn about, ring the changes, sway to and fro, shift to and fro, change and change about, waffle, blow with the wind (irresolute), oscillate, vibrate between, two extremes, oscillate between, two extremes, alternate, have as man phases as the moon.
Doubt
VB
disbelieve, discredit, not believe, misbelieve, refuse to admit, refuse to believe, doubt, be doubtful, doubt the truth of, be skeptical as to, diffide, distrust, mistrust, suspect, smoke, scent, smell a rat, have doubts, harbor doubts, entertain doubts, suspicions, have one's doubts, demure, stick at, pause, hesitate, scruple, stop to consider,
waver, hang in suspense, hang in doubt, throw doubt upon, raise a question, bring in, call in question, question, challenge, dispute, deny, cavil, cause a doubt, raise a doubt, start a doubt, suggest a doubt, awake a doubt, make suspicion, ergotize, startle, stagger, shake one's faith, shake one's belief, stagger one's faith, stagger one's belief.