My sister is very vacillating; she takes a long time to decide what she wants to wear.
His tendency to vacillate makes him a poor leader.
i don't know nor don't care either.
Vacillate - to waver in opinion or mind; be indecisive or irresolute Sentence: Her mood vacillated between hope and despair.
She'll vacillate between the two options and have difficulty making a decision.