腦囟未生埋 (nou5 seon2 mei6 saang1 maai4) — childish, naive, immature (lit., "the fontanel has not yet grown over") in Cantonese
nouˏ₅腦seonˊ²囟meiˍ₆未saangˉ¹生maaiˎ₄埋简 脑囟未生埋
Mandarin Pinyin: nao3 xin4 wei4 sheng1 mai2
Meaning of 腦囟未生埋
nounchildish, naive, immature (lit., "the fontanel has not yet grown over")