late 14c., from Late Latin fornicator, agent noun from fornicat-, stem of fornicari "to fornicate" (see fornication). Of the fem. forms, fornicatrice is c. 1500, fornicatrix 1580s, fornicatress 1590s.
formulate
formulation
Fornax
fornicate
fornication
fornicator
fornix
forsake
forsaken
forsook
forsooth