洞悉

dòngxī
to clearly understand

CEDICT

to clearly understand; to grasp

Wiktionary

明白、通曉。

重編國語辭典

Entry Composition

1 洞 dòng
  1. cave
  2. hole
  3. zero (unambiguous spoken form when spelling out numbers)

classifier: 個
2 悉 xī
  1. in all cases
  2. know