1. (v. t.) To move one way and the other; to reel or stagger; to waver; as, to vacillate between two choices\.

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

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