n.

1. 翻转；逆转；废弃；取消；颠倒

n.

1. a change to an opposite direction, position, or course of action:
   a dramatic reversal in population decline.
   ▸Law  an annulment of a judgement made by a lower court or authority.
   ▸an adverse change of fortune.
2. Photography  direct production of a positive image from an exposed film or plate.