卖哑药

Traditional (Taiwan): 賣啞藥

màiyǎyào ㄇㄞˋ ㄧㄚˇ ㄧㄠˋ

    • to speak cryptically
    • to say nothing and leave others guessing

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
sell mute medicine
Meaning
To speak cryptically or deliberately say nothing, leaving others unable to work out what you mean. Mildly critical.

Sources