fatuous	adjective	complacently or inanely foolish; silly
feckless	adjective	weak, ineffective
fecund	adjective	fruitful in offspring or vegetation; prolific
felicity	noun	something that causes happiness
fervid	adjective	very hot; burning
fetter	noun	a chain or shackle for the feet
finical	adjective	exacting especially about details; finicky
flax	noun	the fiber of the flax plant especially when prepared for spinning
florid	adjective	tinged with red; ruddy; marked by emotional or sexual fervor
foible	noun	the part of a sword or foil blade between the middle and point
foppish	adjective	like a man who pays too much attention to his clothes
forbearance	noun	patience willingness to wait
forswear	verb	to make a liar of (oneself) under or as if under oath
frenetic	adjective	frenzied, frantic
froward	adjective	habitually disposed to disobedience and opposition
fulmination	noun	thunderous verbal attack with noise and violence