耍二百五

shuǎ'èrbǎiwǔ ㄕㄨㄚˇ ㄦˋ ㄅㄞˇ ㄨˇ

    • to behave rashly and foolishly

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
show off two-hundred-and-fifty
Meaning
To behave rashly and foolishly, like a fool. Mocking. 二百五 is a slang term for a fool.

Sources