oscillate
intransitive verb
definition 1: to swing steadily and repeatedly back and forth.
example: As the fan oscillates, different areas of the room get a breeze.
My windshield wipers make a squeaky noise as they oscillate.
definition 2: to waver between different or opposed opinions, conditions, or courses of action; vacillate.
example: I’m still oscillating between staying at my current job and accepting that company’s offer.
definition 3: to vary or cause variances between opposite extremes, usually as a repeated and regular fluctuation.
example: The stock market has a tendency to oscillate.