篤背脊 backstab

用壞話在背後中傷某人, 打小報告的意思。

不知道是否英文直接翻譯得來的香港俗語, 還是香港俗語影響英文, 定還是巧合?

英文剛剛是 backstab, stab him/her in the back.

(名詞) backstabbing

(參考成語) 小人 backstabber

References:

"to attack someone (especially verbally) unfairly in a deceitful, underhand or treacherous manner, especially when they're not present in the place or situation that it happens, as if stabbing them in the back" yourdictionary.com