薯頭薯腦 [－头－脑]

Jyutping syu4 tau4 syu4 nou5
Pinyin shǔ tóu shǔ nǎo

Definitions (CC-CANTO)
  1. being stupid and obtuse
Definitions (粵典–words.hk)
  1. 語句
    形容​人​嗰​樣​睇​落​去​唔​醒目
    stupid looking, stupid; literally "potato head and potato brain"
Definitions (Kaifangcidian)
  1. 笨頭笨腦 – 笨头笨脑