挨闷棍

Traditional (Taiwan): 挨悶棍

áimēngùn ㄞˊ ㄇㄣ ㄍㄨㄣˋ

    • to suffer a sudden heavy blow
    • to be ambushed

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
to be hit with a sudden club
Meaning
To suffer a sudden heavy blow when unprepared, such as a shock setback or an ambush.

Sources