先天

xiāntiān
  1. embryonic period (contrasted with 后天 hòutiān)
  2. inborn; innate; natural

CEDICT

Entry Composition

1 先 xiān
  1. beforehand; first; earlier
  2. at first; originally
  3. for the time being; for now
  4. (prefix) my late (in referring to deceased relatives older than oneself)
2 天 tiān
  1. day
  2. sky
  3. heaven