前所未闻

前所未聞
qiánsuǒwèiwén
(idiom) unheard-of; unprecedented

CEDICT

从来未曾听说过。

重編國語辭典

Examples

这前所未闻, 犯罪嫌疑人的律师竟然是真正的罪魁祸首。

It's totally without precedent for the suspect's attorney to be the true culprit.

Source: Tatoeba

Entry Composition

1 前 qián
  1. front
  2. forward
  3. ahead
  4. first
  5. top (followed by a number)
  6. future
  7. ago
  8. before
  9. BC (e.g. 前293年)
  10. former
  11. formerly
2 所 suǒ
  1. actually
  2. place
  3. classifier for houses, small buildings, institutions etc
  4. that which
  5. particle introducing a relative clause or passive

classifier: 個
3 未 wèi
  1. not yet
  2. did not
  3. have not
  4. not
  5. 8th earthly branch: 1-3 p.m., 6th solar month (7th July-6th August), year of the Sheep
  6. ancient Chinese compass point: 210°
4 闻 wén
  1. to hear
  2. news
  3. well-known
  4. famous
  5. reputation
  6. fame
  7. to smell
  8. to sniff at