先祖

xiānzǔ
  1. (literary) my deceased grandfather
  2. (literary) ancestors

CEDICT

literary

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 祖 zǔ
  1. ancestor
  2. forefather
  3. grandparents