- frequent
- freezer
- fl oz
- flab
- flabbergast
- freak
- flag
- flag-mast
- flaming
- flamy
- flare up
- flash card
- flash cube
- flat bottomed
- frayed
- flat ladle
- flat rate
- flat spin
- flee from
- fleer
- flench
- flesh
- fraud
- frankly
- fleshy
- frank
- flexion
- flick
- francophile
- franchise
- framework
- frame
- fragmented data
- fluoride
- flurried
- fluted
- fluxionary
- fly go out of the window
- fly into rage
- fly of the handle
- fly-fishing
- foible
- forsake
- formless
- formidably
- formidable
- folder
- foliage
- formative
- forlorn
- frivolous
- frill
- free of taxes
- forhood
- foolish fellow
- foot movement
- foot stone
- football pool
- forehead
- foundling
- forecast
- foreboding
- fuss
- foregoing
- foreign country
- foreigner
- foreman, forewoman
- fore-gift
- foothardy
- foot
- formic
- formica compressa
- fornication
- forswear
- forte
- foyer
- foolproof
- fractious
- fragile
- frail
- frame-up
- frantic
- fratricide
- foolish
- freely
- foolery
- foodie
- fresh butter
- food stuff
- fresh-water snail
- freshman, freshwoman
- friction
- friendless
- folk memory
- folk art
- foldaway
- found
- foist
- front
- foil