facetious :: humorous; jocular

facile :: easy; expert

factious :: inclined to form factions; causing dissension

factitious :: artificial; sham

fain :: gladly

fallacious :: misleading

fallible :: liable to err

fallow :: plowed but not sowed; uncultivated

fancied :: imagined; unreal

fanciful :: whimsical; visionary

fantastic :: unreal; grotesque; whimsical

fastidious :: difficult to please; squeamish

fatuous :: foolish; inane

fawning :: courting favor by cringing and flattering

feasible :: practical

felicitous :: apt; suitably expressed; well chosen

fell :: cruel; deadly

fervent :: ardent; hot

fervid :: ardent

fetid :: malodorous

fickle :: changeable; faithless

fictitious :: imaginary

filial :: pertaining to a son daughter

finicky :: too particular; fussy

finite :: limited

fitful :: spasmodic; intermittent

flaccid :: flabby

flagging :: weak; drooping

flagrant :: conspicuously wicked

flamboyant :: ornate

fledgling :: inexperienced

florid :: flowery; ruddy

foolhardy :: rash

foppish :: vain about dress and appearance

forensic :: suitable to debate or courts of law

formidable :: menacing; threatening

fortuitous :: accidental; by chance

fractious :: unruly

frantic :: wild

fraudulent :: cheating; deceitful

fraught :: filled

frenetic :: frenzied; frantic

frenzied :: madly excited

frigid :: intensely cold

frolicsome :: prankish; gay

froward :: disobedient; perverse; stubborn

frowzy :: slovenly; unkempt; dirty

fulsome :: disgustingly excessive

funereal :: sad; solemn

furtive :: stealthy

fustian :: pompous; bombastic