filter vs. undergo
filter vs. strain
firework vs. pyrotechnic
finder vs. viewfinder
finder vs. spotter
faucet vs. spigot
finger vs. fingerbreadth
finger vs. thumb
fingerboard vs. fingerpost
feature vs. lineament
feature vs. have
feature vs. sport
flotsam vs. jetsam
folder vs. leaflet
folder vs. pamphlet
folderal vs. gimcrack
falderol vs. gimcrack
frill vs. gimcrack
frill vs. ruff
foliage vs. leaf
foliage vs. leafage
fluegelhorn vs. flugelhorn
folio vs. leaf
folio vs. pagination
folio vs. paging
flume vs. gulch
flatware vs. silver
fluoroscope vs. roentgenoscope
fixings vs. trimmings
fixings vs. ingredient
footbridge vs. overcrossing
fizgig vs. gig
footing vs. ground
footing vs. terms
flageolet vs. haricot
footlocker vs. locker
firelock vs. flintlock
flute vs. fluting
flagpole vs. flagstaff
footrest vs. footstool
footstool vs. ottoman
footstool vs. tuffet
flail vs. lam
flail vs. thresh
footgear vs. footwear
flange vs. rim
flannel vs. gabardine
flannel vs. washcloth
flannel vs. washrag
fo'c'sle vs. forecastle
floor vs. flooring
floor vs. level
floor vs. shock
flap vs. flaps
flap vs. pother
flap vs. roll
foreground vs. spotlight
foreground vs. highlight
fob vs. trick
forge vs. smithy
forge vs. shape
forge vs. hammer
forge vs. spirt
forge vs. spurt
flashboard vs. flashboarding
flashlight vs. torch
foghorn vs. fogsignal
foible vs. mannerism
flask vs. flaskful
foil vs. hydrofoil
foil vs. spoil
foil vs. transparency
fuze vs. priming
fusee vs. priming
fusee vs. fuzee
fort vs. fortress
fuzee vs. priming
fort vs. garrison
fort vs. fortify
fringe vs. outskirt
fringe vs. periphery
fustian vs. rant
fundament vs. tail
front vs. movement
forepart vs. front
front vs. presence
front vs. look
foundry vs. metalworks
fount vs. fountain
fountain vs. jet
fountain vs. spring
framework vs. model
fret vs. sweat
fret vs. rub
fret vs. grate
fret vs. rankle
fret vs. rag
fret vs. gall
furrow vs. line
furrow vs. rut
furrow vs. wrinkle
fuse vs. priming
foodstuff vs. grocery
fireside vs. hearth
firebomb vs. incendiary
fretsaw vs. jigsaw
fretwork vs. lattice
fenestella vs. lunette
fixer vs. methadone
fixer vs. mender
fixer vs. repairer
fosse vs. moat
fradicin vs. neomycin
feedbag vs. nosebag
footstall vs. pedestal
footpath vs. pathway
flowerpot vs. pot
fragment vs. shard
fragment vs. fragmentize
fragment vs. fragmentise
fishgig vs. gig
fireroom vs. stokehold
fastness vs. stronghold
fastness vs. speed
flyswatter vs. swatter
flyswat vs. swatter
fiddle vs. violin
fiddle vs. tinker
fiddle vs. monkey
fiddle vs. play
fiddle vs. goldbrick
fondness vs. heart
fruit vs. yield
fruit vs. set
frigidity vs. frigidness
faineance vs. idleness
friskiness vs. frolicsomeness
friskiness vs. sportiveness
frankness vs. outspokenness
forthrightness vs. frankness
forwardness vs. readiness
forwardness vs. pushiness
fluency vs. smoothness
flatness vs. languor
flatness vs. mat
flatness vs. planeness
foolhardiness vs. recklessness
fleck vs. spot
flightiness vs. whimsicality
fairness vs. paleness
furtiveness vs. sneakiness
furtiveness vs. stealthiness
format vs. formatting
format vs. initialize
format vs. initialise
flexibility vs. flexibleness
flexibility vs. tractability
flexibility vs. tractableness
femininity vs. muliebrity
formidability vs. toughness
focus vs. stress
focalize vs. focus
focalise vs. focus
focus vs. sharpen
fogginess vs. softness
fogginess vs. murkiness
fuzziness vs. softness
flammability vs. inflammability
faintheartedness vs. faintness
flamboyance vs. floridness
flamboyance vs. floridity
flamboyance vs. showiness
fussiness vs. irritability
fingermark vs. fingerprint
fixedness vs. unalterability
fixedness vs. immobility
fixedness vs. stationariness
fixity vs. immutability
fluidity vs. fluidness
fluidity vs. liquidity
fluidity vs. liquidness
fluidity vs. runniness
felicitousness vs. felicity
felicity vs. happiness
fineness vs. powderiness
fineness vs. thinness
fitness vs. fittingness
fitness vs. seaworthiness
fitfulness vs. jerkiness
fluctuation vs. wavering
fluctuation vs. variation
factuality vs. factualness
firmness vs. steadiness
firmness vs. resolution
firmness vs. soundness
foreignness vs. strangeness
freshness vs. insolence
freshness vs. novelty