Source : Webster's Revised Unabridged Dictionary (1913)

Fornicator \For"ni*ca`tor\, n. [F. fornicateur, OF. fornicator,
   from L. fornicator.]
   An unmarried person, male or female, who has criminal
   intercourse with the other sex; one guilty of fornication.

Source : WordNet®

fornicator
     n : someone who commits adultery or fornication [syn: {adulterer}]