殫心 [殚－]

Jyutping daan1 sam1
Pinyin dān xīn

Definitions (CC-CEDICT)
  1. to devote one's entire mind
Definitions (Wiktionary)
  1. verb, literary
    to do with all one's heart
  2. adv, literary
    wholeheartedly
    (syn.) 悉心, 经心, 一心, 用心, 經心, 全心, 入心