behind someone's back
US /bɪˈhaɪnd ˈsʌm.wʌnz bæk/
UK /bɪˈhaɪnd ˈsʌm.wʌnz bæk/
1.
背著某人, 在某人背後
without someone's knowledge or without telling them
:
•
I can't believe she talked about me behind my back.
我不敢相信她在我背後議論我。
•
They made the decision behind his back.
他們背著他做了這個決定。