水中撈月 [－－捞－]

Jyutping seoi2 zung1 laau4 jyut6
Pinyin shuǐ zhōng lāo yuè

Definitions (CC-CEDICT)
  1. lit. to scoop the moon out of the water (idiom)
  2. a hopeless endeavor
Definitions (Wiktionary)
  1. phrase, figuratively, idiomatic
    to make a hopeless, futile or vain effort at doing something; to ask for the moon
Definitions (Kaifangcidian)
  1. （沒有對應漢語詞彙）