鸡毛信

Traditional (Taiwan): 雞毛信

jīmáoxìn ㄐㄧ ㄇㄠˊ ㄒㄧㄣˋ

    • urgent letter
    • urgent notice or message

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
chicken-feather letter
Meaning
Formerly an urgent letter with a feather stuck in it to show it must be rushed; now any urgent notice or message.

Sources