Thayer's Greek Lexicon

 1. illicit sexual intercourse
  1) adultery, fornication, homosexuality, lesbianism, intercourse
with animals etc.
  2) sexual intercourse with close relatives; Lev. 18
  3) sexual intercourse with a divorced man or woman; Mk. 10:11,12
2. metaph. the worship of idols
  1) of the defilement of idolatry, as incurred by eating the
sacrifices offered to idols