知己

zhījǐ
  1. to know oneself
  2. to be intimate or close
  3. intimate friend

CEDICT

Entry Composition

1 知 zhī
  1. to know
  2. to be aware
2 己 jǐ
  1. self
  2. oneself
  3. sixth of the ten Heavenly Stems 十天干 shítiāngān
  4. sixth in order
  5. letter "F" or Roman "VI" in list "A, B, C", or "I, II, III" etc
  6. hexa