知音

zhīyīn
  1. intimate friend
  2. soul mate

CEDICT

  1. (literary, literal) to have a thorough understanding of music; to be proficient in music
  2. friend keenly appreciative of one's talents; bosom friend; intimate friend; soul mate
  3. to have a thorough understanding of music; to be proficient in music

Wiktionary

春秋時，俞伯牙善鼓琴，鍾子期善聽琴。當伯牙彈琴志在高山時，子期便從琴音感到峨峨若泰山；當伯牙志在流水時，子期又感到洋洋若江河。子期死後，伯牙便絕弦不彈，因為再也沒有人能像子期那樣懂得他的音樂了。見《列子．湯問》。後比喻了解自己的知心朋友。

重編國語辭典

Entry Composition

1 知 zhī
  1. to know
  2. to be aware
2 音 yīn
  1. sound
  2. noise
  3. note (of musical scale)
  4. tone
  5. news
  6. syllable
  7. reading (phonetic value of a character)

Related entries

摯友 zhìyǒu
  1. intimate friend
  2. close friend
知交 zhījiāo intimate friend
膩友 nìyǒu intimate friend
知己 zhījǐ
  1. to know oneself
  2. to be intimate or close
  3. intimate friend
知己难求。

A real friend is like a rare bird.

Source: Tatoeba

同袍 tóngpáo
  1. fellow soldier
  2. comrade
  3. companion
  4. intimate friend