(slang) someone who is young but mature and astute / shrewd / savvy
Definitions (粵典–words.hk)
語句
年紀好細但詭計、鬼主意多。 kids that always have wicked plans and play pranks on others
語句
年紀好細但做啲大人先做嘅行為 (lit.) small as a human and big as a ghost; (fig.) a child capable of thinking, acting and misbehaving like an adult; a child full of tricks
佢人細鬼大,竟然用媽媽啲化妝品扮靚。
佢人细鬼大,竟然用妈妈啲化妆品扮靓。
keoi5 jan4 sai3 gwai2 daai6, ging2 jin4 jung6 maa4 maa1 di1 faa3 zong1 ban2 baan6 leng3. She acts as if she were an adult, using her mum's cosmetics to do make up.