充大人燈

Simplified: 充大人灯

chōngdàrendēng ㄔㄨㄥ ㄉㄚˋ ˙ㄖㄣ ㄉㄥ

    • to act like a grown-up
    • to put on airs

Character by character

Saying俗语俗語

Idiom惯用语 · Rarely used now

Literally
pose as an adult lamp
Meaning
Of a child, to act like a grown-up; more widely, to put on airs. Mocking.

Sources