勞空神 [劳－－]

Jyutping lou4 hung1 san4
Pinyin láo kōng shén

Definitions (Wiktionary)
  1. verb, Xiang
    to bother one's head for nothing
    (syn.) 白费心思, 勞豆殼子神, 白費心思, 劳豆壳子神