孜孜矻矻 [----]

Jyutping zi1 zi1 ngat6 ngat6
Pinyin zī zī kù kù

Definitions (Wiktionary)
  1. adv
    diligently

孜孜矻矻 [----]

Jyutping zi1 zi1 ngat6 ngat6
Pinyin zī zī kū kū

Definitions (CC-CEDICT)
  1. diligently
Definitions (Wiktionary)
  1. adv
    diligently