adverb · repeatedly; over and over again

他反复思考，最后才做出了决定。

verb · to come and go; the recurrence of a condition or return of an illness

感冒虽然好了，但如果不注意很容易反复。

verb · changeable; to upend or reverse one's position or attitude

他这个人情绪反复，让人捉摸不透。