追溯

zhuīsù
  1. lit. to go upstream
  2. to trace sth back to
  3. to date from

CEDICT

Entry Composition

1 追 zhuī
  1. to chase
  2. to pursue
  3. to look into
  4. to investigate
  5. to reminisce
  6. to recall
  7. to court (one's beloved)
  8. to binge-watch (a TV drama)
  9. retroactively
  10. posthumously
=2 溯 sù
  1. to go upstream
  2. to trace the source
=2 溯 sù variant of 溯 sù