交頭接耳

Simplified: 交头接耳

On the HSK 7-9 vocabulary list, at CEFR level C1.

jiāotóujiēěr ㄐㄧㄠ ㄊㄡˊ ㄐㄧㄝ ㄦˇ

    • to whisper to one another's ear

Character by character

Sources