Letter: f
- fire-resisting, airtight, fireproof, flame-proof, foolproof, hermetic, impervious, proof, resistant, shatter-proof, soundproof, tight, watertight, weatherproof
- fire-trap, booby trap, decoy, gin, mine, mousetrap, pitfall, trap
- fire-water, alcohol, booze, budge, drink, grog, juice, liquor, lush, medicine, sauce, spirit, tipple
- firearm, automatic, blowgun, blowpipe, flame-thrower, gun, handgun, heater, musket, peashooter, piece, pistol, repeater, revolver, rifle, rod
- fireball, Thor, alcohol, ball lightning, benzine, bolt, bolt of lightning, briquette, burnable, butane, carbon, chain lightning, charcoal, coal, coke, combustible
- firebrand, Mafioso, agitator, agitprop, beast, berserk, berserker, bomber, brand, brute, burning ember, butane lighter, catalyst, cigarette lighter, cinder, coal
- firecracker, Klaxon, Roman candle, boiler factory, boiler room, bomb, bull-roarer, cap, catcall, cherry bomb, clack, clapper, cracker, cricket, flare, flowerpot
- fired, afire, agog, aroused, atwitter, baked, boiled, braised, broiled, browned, bursting, carried away, coddled, cooked, curried, devilled
- firedamp, breath, cloud, coal gas, damp, effluvium, exhalation, exhaust, exhaust gas, flatus, fluid, foetid air, fume, malaria, miasma, puff of smoke
- firefly, blink, blinking, coruscation, glimmer, glimmering, glisten, glister, glitter, glittering, glow-worm, lantern fly, phosphor, scintilla, scintillation, shimmer
- fireman, autoloader, baggage man, black gang, bungs, butcher, cabin boy, chips, commissary steward, complement, conductor, deckhand, dispatcher, fire brigade, fire fighter, fire warden
- fireplace, ancestral halls, chimney, chimney corner, family homestead, fender, fire screen, fire-guard, fireside, flue, foyer, hearth, hearth and home, hearthstone, hob, home
- fireproof, airtight, bombproof, bulletproof, burglarproof, fire-resisting, flame-proof, foolproof, hermetic, impervious to, insulate, proof, proof against, resistant, rustproof, shatter-proof
- firer, abettor, energizer, gadfly, inspirer, mover, moving spirit, pleader, prime mover, prompter, spark, spark plug, tempter
- fireside, ancestral halls, chimney, chimney corner, family homestead, fender, fire screen, fire-guard, fireplace, flue, foyer, hearth, hearth and home, hearthstone, hob, home
- firewood, Yule clog, backlog, beam, billet, board, boarding, brush, brushwood, clap board, cord, deal, driftwood, faggot, hardwood, kindling
- fireworks, Roman candle, anti-aircraft fire, bomb, cap, cherry bomb, cracker, cross fire, curtain fire, direct fire, dry fire, file fire, fire, fire of demolition, fire-power, firecracker
- firing line, battle line, battle site, battlefield, battleground, combat area, combat zone, enemy line, field, field of battle, field of blood, front line, killing ground, landing beach, line, line of battle
- firing, afflatus, agitation, alcohol, animating spirit, animation, animus, anti-aircraft fire, archery, arousal, benzine, briquette, burnable, butane, carbon, cashiering
- firm hold, bear hug, bite, clamp, clasp, clench, clinch, cling, clutch, death grip, embrace, foothold, footing, grapple, grasp, grip
- firm up, balance, ballast, counterbalance, firm, freeze, hold, immobilize, keep, nail down, pin down, retain, stabilize, steady, stick, thicken
- firm, Christian, abiding, accepted, adamant, agency, airtight, anchored, anneal, approved, at a standstill, atelier, authentic, authoritative, balance, balanced
- firm-minded, forward, importunate, independent, pushy, self-assertive, self-controlled, self-possessed, self-restrained
- firmament, air, azure, blue sky, canopy, canopy of heaven, cerulean, cope, empyrean, ether, heaven, heavens, lift, lifts, sky, starry heaven
- firming, arteriosclerosis, atherosclerosis, hardening, petrification, sclerosis, setting, solidification, tempering
- firmly established, confirmed, dyed-in-the-wool, embossed, engraved, established, etched, graven, implanted, impressed, imprinted, ingrained, ingrown, inveterate, rooted, set
- firmly, adamantly, close, closely, compactly, consistently, constantly, deafeningly, decidedly, decisively, densely, determinedly, devotedly, dourly, earnestly, faithfully
- firmness of mind, concentration, constancy, inflexibility, loyalty, rigidity
- firmness, adherence, allegiance, aplomb, attachment, authenticity, backbone, balance, body, bond, bravery, certainty, closeness, commitment, concentration, congestion
- first aid, cure, medication, regime, treatment
