alternate, back and fill, be here again, bob, bobble, careen, change, circle, coggle, come again, come and go, come around, come round, come round again, come up again, cycle, dangle, dither, ebb and flow, equivocate, flounder, fluctuate, flutter, go through phases, hem and haw, intermit, librate, lurch, nutate, pendulate, pitch, pulsate, pulse, reappear, recur, reel, reoccur, repeat, resonate, return, revolve, ring the changes, rock, roll, roll around, rotate, seesaw, shake, shift, shilly-shally, shuffle, stagger, swag, sway, swing, teeter, teeter-totter, tergiversate, toss, totter, turn, undulate, vacillate, vary, vibrate, wag, waggle, wave, waver, wax and wane, wheel, wheel around, wobble
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.
, vibrate, librate, alternate, undulate, wave, rock, swing, pulsate, beat, wag, waggle, nod, bob, courtesy, curtsy, tick, play, wamble, wabble, dangle, swag, fluctuate, dance, curvet, reel, quake, quiver, quaver, shake, flicker, wriggle, roll, toss, pitch, flounder, stagger, totter, move up and down, bob up and down, pass and repass, ebb and flow, come and go, vacillate, teeter, brandish, shake, flourish.