vacillate

v. sway to and from, fluctuate; hesitate, waver

Verb
1. be undecided about something; waver between conflicting positions or courses of action; "He oscillates between accepting the new position and retirement"
(synonym) hover, vibrate, oscillate
(hypernym) hesitate, waver, waffle
(hyponym) shillyshally
(derivation) hesitation, vacillation, wavering
2. move or sway in a rising and falling or wavelike pattern; "the line on the monitor vacillated"
(synonym) fluctuate, waver
(hypernym) swing
(verb-group) fluctuate
(derivation) swing, swinging, vacillation

v. sway, flicker, shake, falter, swim, totter, waver, wobble, wabble, reel

(v. t.)
To move one way and the other; to reel or stagger; to waver.
  

(v. t.)
To fluctuate in mind or opinion; to be unsteady or inconstant; to waver.
  

Synonyms and related words:
alternate, back and fill, bob, bobble, careen, change, changeable, chop and change, coggle, dally, dallying, dangle, demurring, dickey, dillydallying, dither, double-minded, doubtful, doubting, ebb and flow, eccentric, equivocate, erratic, falter, faltering, fickle, fiddle-faddle, flounder, fluctuant, fluctuate, fluctuating, flutter, go through phases, halt, halting, hang in doubt, hem and haw, hesitant, hesitate, hesitating, inconstant, indecisive, insecure, irresolute, librate, lurch, mercurial, nutate, oscillate, oscillating, pendulate, pendulous, pitch, reel, resonate, ring the changes, rock, roll, rootless, seesaw, shake, shaky, shift, shifting, shilly-shally, shilly-shallying, shuffle, stagger, stop to consider, swag, sway, swing, teeter, teeter-totter, tentative, tergiversate, think twice, timid, toss, totter, turn, uncertain, unresolved, unsettled, unstable, unsteady, unsure, vacillating, vacillatory, vary, vibrate, volatile, wag, waggle, wave, waver, wavering, wax and wane, weak, weak-kneed, whiffle, wigwag, wobble, wobbly