鬼鬼祟祟

guǐ guǐ suì suì

sneaky; furtive

Character by character

鬼guǐ
ghost

祟suì
haunt

那个人在门口鬼鬼祟祟的，不知道想干什么。

That man's been skulking by the door. Who knows what he's up to.

Tone: negative (criticism).

祟 suì (to haunt) is not 崇 chóng. Usual frame: 鬼鬼祟祟的.

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