waver; fluctuate; move back and forth uncertainly between two alternatives
He is a naturally indecisive person, so whenever he is forced to make a choice, he tends to vacillate between the two alternatives without being able to decide.
vacillare (sway to and fro, waver, hesitate, be untrustworthy) (Latin)
Sounds like oscillate. So something which moves from one position to another position. Vacillate=VACI bhi bahut LATE ho gaya hai. Now you don't VACILLATE between what you are going to wear for the party.