打死老虎

dǎsǐlǎohǔ ㄉㄚˇ ㄙˇ ㄌㄠˇ ㄏㄨˇ

    • to attack someone who has lost power and cannot hit back

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
beat a dead tiger
Meaning
To attack someone who has already lost power and can no longer hit back. Critical or mocking.

Sources