To flip-flop is to change your opinion, and often to change it again — to face one way, then the other. We use it most about people in public, especially politicians: yes in March, no in June. It is informal and usually unkind. The speaker is not praising a careful new thought; they are saying you cannot trust this stand.

To flip-flopFlip-flop（變來變去） is to change your opinion是改變自己的立場，and often to change it again而且常常又改回去——to face one way, then the other先面向這邊，再面向那邊。We use it most about people in public這個字最常用在公眾人物身上，especially politicians尤其是政治人物：yes in March, no in June三月說好，六月又說不要。It這 is informal and usually unkind是口語用法，而且通常不太客氣。The speaker is not praising a careful new thought說話的人不是在稱讚你經過深思熟慮而改變，they are saying you cannot trust this stand而是在說：你這個立場不可信。

You can also use it as a noun: “another flip-flop on tax.” Though actually, the same words name the open shoes that slap your heel as you walk. That sound — flip, flop — is probably where the word was born: it copies the noise. The opinion meaning takes the picture of something that slaps over and back.

You can also use it as a noun你也可以把它當名詞用："another flip-flop on tax."「稅務上又一次大轉彎」。Though actually但其實，the same words name the open shoes that slap your heel as you walk同一個字也指走路時會拍打腳跟的那種涼鞋。That sound — flip, flop —那個聲音——flip、flop—— is probably where the word was born大概就是這個字誕生的地方：it copies the noise它模仿的是那個聲音。The opinion meaning講立場的那個意思 takes the picture of something that slaps over and back用的就是那個啪一聲翻過去又翻回來的畫面。

(In machines, a flip-flop is a different thing again, a tiny on-off switch; that is not this sense.) If someone learns and honestly changes once, “they changed their mind” is fairer than flip-flop.

(In machines, a flip-flop is a different thing again, a tiny on-off switch; that is not this sense.)（在機器裡，flip-flop 又是另一回事，是一種很小的開關電路；那不是這個意思。）If someone learns and honestly changes once如果一個人是學到東西後誠實地改變一次想法，"they changed their mind" is fairer than flip-flop說「他們改變主意了」會比 flip-flop 公平一點。