挖空心思 [－－－－]

Jyutping waat3 hung1 sam1 si1
Pinyin wā kōng xīn sī

Definitions (Wiktionary)
  1. verb, derogatory, usually
    to rack one's brains; to search everything for an answer
    (syn.) 想心想肝

挖空心思 [－－－－]

Jyutping waat3 hung1 sam1 si1
Pinyin wā kōng xīn si

Definitions (CC-CEDICT)
  1. to dig for thoughts (idiom); to search everything for an answer
  2. to rack one's brains