深知

shēnzhī
to know well; to be fully aware of

CEDICT

to know very well; to understand thoroughly

Wiktionary

十分瞭解。

重編國語辭典

Entry Composition

=1 深 shēn old variant of 深 shēn
=1 深 shēn deep (lit. and fig.)
2 知 zhī
  1. to know
  2. to be aware