• 鏤骨るこつ

  painstaking efforts

• 鏤刻るこく

  engraving, carving (into)

• 撥鏤ばちる

  engraving of lacquer-stained ivory (popular during the Tang dynasty)

• 彫心鏤骨ちょうしんるこつ

  laborious work, lucubration, lucubrations, painstakingly polishing a piece of literary work