磨穿鐵硯 [－－铁砚]

Jyutping mo4 cyun1 tit3 jin2
Pinyin mó chuān tiě yàn

Definitions (粵典–words.hk)
  1. x

磨穿鐵硯 [－－铁砚]

Jyutping mo4 cyun1 tit3 jin6
Pinyin mó chuān tiě yàn

Definitions (CC-CEDICT)
  1. to grind one's way through an ink stone
  2. to persevere in a difficult task (idiom)
  3. to study diligently (idiom)
Definitions (Wiktionary)
  1. phrase, figuratively, idiomatic
    to show extreme diligence in one's studies