不管三七二十一

bùguǎnsānqī'èrshíyī ㄅㄨˋ ㄍㄨㄢˇ ㄙㄢ ㄑㄧ ㄦˋ ㄕˊ ㄧ

    • regardless of the consequences
    • recklessly relying on a hopelessly optimistic forecast

Character by character

Saying俗语俗語

Idiom惯用语 · In everyday use

Literally
not caring that three times seven is twenty-one
Meaning
Acting recklessly regardless of the consequences or the facts. Usually critical; like "regardless of the consequences".

Sources