1. false witness a person who deliberately gives false testimony
  2. falseness the state of being false or untrue
  3. fleetness rapidity of movement
  4. fastness a rate (usually rapid) at which something happens
  5. flightiness the trait of acting unpredictably
  6. illicitness the quality of not conforming strictly to law
  7. vastness unusual largeness in size or extent or number
  8. fulsomeness excessive but superficial compliments given with affected charm
  9. floridness extravagant elaborateness
  10. faultiness the state of being defective
  11. frostiness coldness as evidenced by frost
  12. licitness the quality of strictly conforming to law
  13. validness the quality of having legal force or effectiveness
  14. fluidness the property of flowing easily
  15. fallaciousness result of a fallacy or error in reasoning
  16. flatness the property of having two dimensions
  17. false pretense (law) an offense involving intent to defraud and false representation and obtaining property as a result of that misrepresentation
  18. felicitousness pleasing and appropriate manner or style
  19. blessedness a state of supreme happiness
  20. pellucidness passing light without diffusion or distortion