不摸底

bùmōdǐ ㄅㄨˋ ㄇㄛ ㄉㄧˇ

    • to be in the dark about the true situation

Character by character

Saying俗语俗語

Idiom惯用语 · Widely known

Literally
not feeling the bottom
Meaning
Not knowing the true situation. Colloquial; "in the dark about the facts".

Sources