鑽堅仰高 [钻坚－－]

Jyutping zyun1 gin1 joeng5 gou1
Pinyin zuān jiān yǎng gāo

Definitions (CC-CEDICT)
  1. lit. looking up to it, it gets higher; boring into it, it gets harder (idiom) (from Analects)
  2. fig. to delve deeply into one's studies
  3. meticulous and diligent study