oscillating

(verb) be undecided about something; waver between conflicting positions or courses of action. Synonyms: hover, vibrate, vacillate, oscillate. Example: "He oscillates between accepting the new position and retirement."

(verb) move or swing from side to side regularly. Synonyms: oscillate, vibrate. Example: "The needle on the meter was oscillating."

(adj) having periodic vibrations. Synonyms: oscillatory.