behind someone's back

US /bɪˈhaɪnd ˈsʌm.wʌnz bæk/
UK /bɪˈhaɪnd ˈsʌm.wʌnz bæk/
"behind someone's back" picture
1.

من وراء ظهر شخص, دون علم شخص

without someone's knowledge or without telling them

:
I can't believe she talked about me behind my back.
لا أصدق أنها تحدثت عني من وراء ظهري.
They made the decision behind his back.
لقد اتخذوا القرار من وراء ظهره.