It seems like you vacillate between 10 and 20 members at any given time.
Van der Sloot appears to vacillate between apologetic and aloof in his response, captured on hidden camera.
I kind of self-edit that out of the history, but they did vacillate for quite a while.
The compass began to vacillate, and no longer pointed toward the north; this confused both Columbus and his pilots.
Long did he vacillate whether Tom Keane should not be arrested on suspicion.
The Lamas are trained to wrangle and dispute and defer and vacillate.
They vacillate, conforming now to the interest of the wage-workers, now to the interest of the employers.
The reasoning power becomes weakened and the steadiest mind commences to vacillate.
As if it were possible to wait now, to weigh, vacillate, hesitate!
Why do you vacillate, and keep us all in the dark as to what you mean?
1590s, "to sway unsteadily," from Latin vacillatum, from vacillare (see vacillation). Meaning "to waver between two opinions or courses" is recorded from 1620s. Related: Vacillated; vacillates; vacillating.