生水芋頭 [－－－头]

Jyutping saang1 seoi2 wu6 tau2
Pinyin shēng shuǐ yù tou

Definitions (粵典–words.hk)
  1. 名詞
    煮熟​之後硬​滑​而​唔​會​淋​晒​嘅​芋​頭
    taro root that remains hard after cooking
  2. 名詞
    傻下​傻​下​，​唔​醒目​或者​唔​係​好​正常​嘅​人
    (literally: watery taro root) strange, odd, crazy, weird

生水芋頭 [－－－头]

Jyutping saang1 seoi2 wu6 tau4
Pinyin shēng shuǐ yù tou

Definitions (CC-CANTO)
  1. stupid person; fool (slang)