頭大冇腦 [头－－脑]

Jyutping tau4 daai6 mou5 nou5
Pinyin tóu dà mǎo nǎo

Definitions (CC-CANTO)
  1. dumb; nobhead (spoken)
Definitions (粵典–words.hk)
  1. 語句、俚語
    形容​一個​人​好​蠢
    stupid, empty-headed; literally: big head no brain