- fireplug
- firepower
- fireproof
- fire-raising
- fire-resistant
- fire-resisting
- fire-resistive
- fire-retardant
- fireroom
- fireside
- firestone
- firestorm
- fire-swallower
- firethorn
- firetrap
- firewall
- firewater
- fireweed
- fire-wheel
- firewheel tree
- firewood
- firework
- fire-worship
- firing
- firing chamber
- firing line
- firing mechanism
- firing off
- firing party
- firing pin
- firing range
- firing squad
- firkin
- firm
- firm omelet
- firm up
- firmament
- firmamental
- firmer chisel
- firmiana
- firmiana simplex
- firmly
- firmness
- firmness of purpose
- firmware
- first
- first aid
- first amendment
- first and last
- first appearance
- first balcony
- first baron beveridge
- first baron kelvin
- first baron lytton
- first baron macaulay
- first baron marks of broughton
- first baron passfield
- first baron rutherford
- first baron rutherford of nelson
- first baron tennyson
- first base
- first baseman
- first battle of ypres
- first blush
- first cause
- first class
- first council of constantinople
- first council of lyons
- first council of nicaea
- first cousin
- first cranial nerve
- first crusade
- first degree
- first derivative
- first duke of marlborough
- first duke of wellington
- first earl kitchener of khartoum
- first earl of beaconsfield
- first earl of chatham
- first earl of orford
- first earl wavell
- first epistle of john
- first epistle of paul the apostle to the corinthians
- first epistle of paul the apostle to the thessalonians
- first epistle of paul the apostle to timothy
- first epistle of peter
- first epistle to the corinthians
- first epistle to the thessalonians
- first epistle to timothy
- first estate
- first floor
- first gear
- first half
- first harmonic
- first in first out
- first lady
- first language
- first lateran council
- first law of motion
- first law of thermodynamics
- first lieutenant
- first light
- first lord of the treasury
- first marquess cornwallis
- first mate
- first moment
- first mortgage
- first name
- first of all
- first of may
- first of october antifascist resistance group
- first off
- first offender
- first period
- first person
- first principle
- first quarter
- first reading
- first rudiment
- first sacker
- first sergeant
- first state
- first step
- first stomach
- first strike
- first team
- first trimester
- first vatican council
- first viscount haldane of cloan
- first viscount nuffield
- first visual area
- first water
- first world war
- first-aid kit
- first-aid station
- firstborn
- first-class
- first-class honours degree
- first-class mail
- first-come-first-serve
- first-degree burn
- firsthand
- firstly
- first-nighter
- first-order correlation
- first-place finish
- first-rate
- first-rater
- first-string
- first-year
- firth
- firth of clyde
- firth of forth
- fisa
- fisc
- fiscal
- fiscal policy
- fiscal year
- fiscally
- fischer
- fischer's slime mushroom
- fish
- fish and chips
- fish ball
- fish bowl
- fish cake
- fish chowder
- fish doctor
- fish duck
- fish eagle
- fish family
- fish farm
- fish filet
- fish fillet
- fish finger
- fish fly
- fish fry
- fish fuddle
- fish genus
- fish geranium
- fish glue
- fish hawk
- fish house punch
- fish joint
- fish knife
- fish ladder
- fish loaf
- fish louse
- fish lure
- fish meal
- fish mousse
- fish oil
- fish scale
- fish slice
- fish species
- fish steak
- fish stew
- fish stick
- fish tank
- fishbone