空前

kōngqián
unprecedented

CEDICT

Entry Composition

1 空 kōng
  1. empty
  2. air
  3. sky
  4. in vain
2 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