盞攪 [盏搅]

Jyutping zaan2 gaau2
Pinyin zhǎn jiǎo

Definitions (CC-CANTO)
  1. to do something to no avail
Definitions (粵典–words.hk)
  1. 形容詞
    做​嚟​都​無意義​，​只​係​白​做
    a waste of time and effort
  2. 參看
    盞搞、賺搞