手てのひら返がえし

noun, noun or participle which takes 'suru', intransitive verb

sudden reversal; about-face; flip-flop

Describes a complete and often abrupt change in behavior, opinion, or attitude, as if flipping one's palm. Often used critically. Can be used as a noun or with する to mean 'to do a complete about-face'.

• 昨日きのうまで反はん対たいしていたのに、今日きょうは賛さん成せいするなんて、手てのひら返がえしもいいところだ。

  He was against it until yesterday, and now he's for it today—what a complete flip-flop.

• 彼かれは上じょう司しの前まえで手てのひら返がえしをして、自じ分ぶんの意い見けんを変かえた。

  He did an about-face in front of his boss and changed his opinion.