2 letters:
er, or

3 letters:
air, ayr, bur, cur, ear, err, fir, for, fur, ire, mir, nor, oar, ore, per, sir, tor, war

4 letters:
abor, amir, bare, bear, beer, bier, birr, blur, boar, boer, boor, bore, burr, care, core, cure, dare, dear, deer, dire, doer, door, dour, emir, fair, fare, fear, fehr, fire, fore, four, gear, gere, gore, hair, hare, hear, heir, here, herr, hire, hoar, hour, igor, jeer, jour, lair, lear, lohr, lore, lour, lure, lyre, mare, meir, mere, mire, moor, more, near, pair, pare, pear, peer, pier, poor, pore, pour, pure, purr, rare, rear, roar, ruhr, sear, seer, sere, slur, soar, sore, sour, spur, stir, sure, tear, thor, tier, tore, torr, tour, tyre, veer, ware, wear, weir, were, wire, wore, year, yore, your

5 letters:
abhor, adore, afire, amour, ashir, assur, astir, aware, blair, blare, blear, chair, cheer, chirr, chore, churr, clear, corps, crore, decor, defer, demur, deter, dower, drear, flair, flare, floor, flour, freyr, glare, greer, grier, incur, infer, inter, inure, loire, moire, moore, murre, myrrh, ne'er, occur, queer, quire, recur, refer, sapir, scare, score, scour, senor, share, shear, sheer, sherr, shire, shirr, shore, smear, snare, sneer, snore, spare, spear, spire, spoor, spore, stair, stare, steer, store, swear, swore, their, there, vanir, we're, where, whirr, whore, yasir, zaire

6 letters:
abjure, adhere, adjure, admire, affair, aflare, allure, appear, ashore, aspire, assure, before, beware, career, claire, cohere, concur, confer, demure, detour, drawer, eclair, endear, endure, ensure, exmoor, expire, fakeer, galore, go for, ignore, immure, impair, impure, inhere, insure, kaffir, lenore, manure, mature, menhir, midair, o'hare, pierre, pindar, poseur, prayer, prefer, prewar, rehear, repair, retire, revere, rigour, safire, salvor, sambur, schorr, secure, severe, shamir, shmear, sphere, square, squire, unfair, unsure, vapour, velour, veneer, vigour, voyeur, you're

7 letters:
affaire, anymore, ask for, astaire, austere, au pair, besmear, big sur, bonaire, bonheur, bugbear, cashier, compare, compeer, compere, cooccur, couture, cry for, danseur, declare, deplore, despair, de jure, ensnare, explore, flexure, forbear, gravure, guinier, hachure, hot air, hot war, houhere, implore, inquire, inshore, inspire, kildeer, languor, liqueur, moliere, nervure, no more, obscure, on tour, opt for, outroar, pasteur, pay for, pioneer, postwar, premier, prepare, procure, rancour, rapport, require, respire, restore, run for, schmear, sincere, soilure, succour, tangier, tarsier, they're, tonsure, try for, tussore, unaware, unclear, upstair, up here, wafture

8 letters:
abhorrer, panderer, answerer, gatherer, batterer, labourer, abampere, allosaur, amanpour, ant bear, barosaur, blue air, boer war, brochure, brumaire, bus fare, cab fare, call for, calm air, care for, car care, car door, cat bear, cavalier, coiffeur, coiffure, coinsure, cold war, day care, debonair, derriere, domineer, done for, due care, elaphure, encolure, engineer, ex-mayor, fall for, feel for, fend for, footgear, footsure, forswear, for sure, frontier, frotteur, give ear, got your, grandeur, handwear, hot-wire, ice bear, immature, iron ore, killdeer, lavalier, lead ore, longueur, look for, low gear, make for, markhoor, monsieur, muleteer, mutineer, offshore, open-air, open air, outscore, overbear, overhear, paramour, parterre, perspire, per year, premiere, put your, reappear, reassure, red deer, reinsure, roe deer, saboteur, sea hare, seigneur, send for, sinecure, souvenir, sun gear, t-square, take for, tamanoir, testiere, transfer, true fir, twoscore, voltaire, what for, wheatear, wirehair

9 letters:
chatterer, slanderer, plasterer, swaggerer, stammerer, flatterer, air corps, allow for, all clear, apatosaur, archosaur, back door, balladeer, bandoleer, bandolier, barn door, basketeer, belvedere, bock beer, brigadier, buccaneer, cafe noir, cannoneer, cared-for, chauffeur, chevalier, chinaware, civil war, class war, cold sore, come near, coon bear, cover for, dark beer, debonaire, disappear, disrepair, downstair, draw near, duty tour, each year, financier, fire door, fourscore, gadgeteer, gazetteer, giant fir, give care, gondolier, go to war, grand fir, great war, grope for, guarantor, guinevere, gum myrrh, hadrosaur, hair care, half door, held dear, high gear, hold dear, holy year, hoped-for, horsehair, inner ear, insincere, interfere, joint fir, leap year, life peer, light air, make pure, make sure, megathere, mouse ear, mule deer, musketeer, musk deer, near beer, next door, nothosaur, once more, open door, outer ear, over here, pap smear, persevere, pistoleer, plump for, plunk for, premature, presbyter, price war, privateer, profiteer, pterosaur, puppeteer, pushchair, quest for, racketeer, raconteur, red scare, rest-cure, root beer, root hair, set afire, shoot for, side door, sightseer, skin care, sloganeer, solitaire, sonneteer, sorry for, speak for, spur gear, stand for, stegosaur, stud mare, sweep oar, take care, taxi fare, that your, trap door, trochlear, volunteer, warrantor, wasteweir, white fir, wild boar, world war, worm gear

10 letters:
macebearer, talebearer, air-to-air, alpine fir, ankylosaur, answer for, auctioneer, balsam fir, bath chair, baudelaire, bear's ear, bevel gear, birch beer, blackamoor, black bear, bombardier, brontosaur, brown bear, budget for, burro deer, called for, camp chair, carabineer, ceratosaur, chandelier, charioteer, child care, civil year, cockleburr, commandeer, cross hair, debonnaire, deck chair, dutch door, easy chair, embouchure, every year, faith cure, false hair, first gear, foursquare, fraser fir, front door, god of war, gondoliere, grand tour, great bear, great care, great year, ground fir, guard hair, halberdier, harpooneer, heretofore, honey bear, ictodosaur, in one ear, in the air, kieselguhr, koala bear, korean war, lawn chair, light beer, light year, liquid air, longed-for, looked-for, louis d'or, lunar year, mal de mer, man-of-war, marsh hare, mens store, middle ear, mouse deer, mouse hare, oregon fir, panda bear, pelycosaur, petit four, pinot noir, plesiosaur, polar bear, polar hare, pubic hair, re-explore, river pear, scotch fir, scrutineer, secretaire, seismosaur, set ashore, set square, shoe store, shop floor, side chair, silver fir, skunk bear, sloth bear, small beer, smoothbore, solar year, stage door, swamp hare, swing door, teddy bear, third gear, threescore, tidal bore, to be sure, to one ear, train fare, trojan war, try square, tug-of-war, uintathere, underscore, water deer, weiss beer, wing chair, wished-for, woody pear

11 letters:
ampere-hour, philanderer, account for, apgar score, arctic hare, balsam pear, beach chair, billionaire, black maire, bronx cheer, buffalo bur, camera care, candidature, candy store, church year, come before, come in for, common year, connoisseur, corythosaur, crimean war, cry out for, dance floor, death chair, dental care, doctrinaire, double door, douglas fir, dressed ore, dromaeosaur, edward lear, fallow deer, first floor, fiscal year, flying mare, french door, gala affair, ginger beer, gomphothere, health care, ichthyosaur, kodiak bear, limited war, litterateur, little bear, looking for, love affair, lowland fir, mexican war, milliampere, millionaire, munich beer, native bear, native pear, ocean floor, pamphleteer, peace corps, peacock ore, planet gear, potty chair, prepare for, press corps, provide for, puff of air, rotogravure, saddle sore, schenk beer, school year, screen door, seckel pear, second gear, sedan chair, six day war, slight care, solar flare, spanish war, spruce beer, squeeze for, stable gear, styracosaur, subway fare, supersedure, syrian bear, take a dare, that you're, tyrannosaur, uncared-for, unhoped-for, uranium ore, vanity fair, vietnam war, volt-ampere, walk on air, what's your, what you're, white maire, wicket door, woolly bear, word square, yacht chair, yearned-for

12 letters:
franc-tireur, manufacturer, anchovy pear, avocado pear, barber chair, barking deer, bartle frere, belgian hare, bevel square, bill of fare, buffer store, camel's hair, ceramic ware, colorado fir, elephant ear, entrepreneur, external ear, far and near, fishing gear, flower store, folding door, garden chair, going ashore, green manure, grizzly bear, ground floor, head of hair, heliogravure, internal ear, in disrepair, king's spear, kuala lumpur, landing gear, latin square, leisure wear, liquor store, lounge chair, magic square, marine corps, marston moor, medical care, morris chair, nursing care, outside door, photogravure, pied-a-terre, powder store, prickly pear, psittacosaur, restaurateur, retail store, savoir-faire, sensory hair, service door, sliding door, sloop of war, soup du jour, standing for, state of war, staurikosaur, swivel chair, times square, time of year, uncalled-for, unlooked-for, unwished-for, varying hare, what is more, white squire, without fear

13 letters:
academic year, army engineer, bartlett pear, bowling score, bring to bear, calendar year, carte du jour, cinnamon bear, conventioneer, country store, crystal clear, european hare, exterior door, feeding chair, folding chair, force majeure, general store, grocery store, haute couture, hospital care, interior door, japanese deer, jewelry store, kangaroo bear, kangaroo hare, laissez-faire, laissez faire, last frontier, lord's prayer, louis pasteur, market square, more and more, musical score, nom de guerre, ordinary care, oriental sore, package store, parquet floor, platonic year, porte-cochere, porter's beer, public square, questionnaire, rocking chair, rouge et noir, snowshoe hare, social affair, steering gear, stinging hair, swinging door, tropical sore, tropical year, virginia deer, wear and tear, windsor chair

14 letters:
accordion door, alligator pear, baseball score, cervical smear, christian year, civil engineer, clothing store, coffee liqueur, commissionaire, compressed air, computer store, concessionaire, discount store, electric chair, elephant's ear, evening prayer, financial year, football score, hardware store, hold still for, know the score, legal transfer, morning prayer, naval engineer, orange liqueur, planetary gear, pneumatic tyre, red silver fir, straight chair, surface-to-air, take the floor, walking on air, warning of war, war to end war, whitetail deer, white lead ore, world premiere, yom kippur war

15 letters:
black marketeer, captain's chair, cauliflower ear, croix de guerre, esprit de corps, first world war, flight engineer, have been there, house of prayer, jewish new year, kilovolt-ampere, marine engineer, mezzanine floor, mining engineer, out of thin air, prisoner of war, reasonable care, reclining chair, responsible for, sabbatical year, santa lucia fir, specialty store, us marine corps, with great care

16 letters:
basketball score, capital of zaire, celestial sphere, come to the fore, department store, diplomatic corps, highway engineer, on a lower floor, pachycephalosaur, pays de la loire, persian gulf war, political sphere, second world war, secretary of war, seven years' war, step to the fore

17 letters:
astronomical year, brace oneself for, castle in the air, convenience store, differential gear, earning per share, english civil war, green douglas fir, implements of war, little chief hare, lowland white fir, military engineer, on a higher floor, overstuffed chair, peloponnesian war, pere david's deer, railroad engineer, software engineer, thirty years' war

18 letters:
aerospace engineer, alaskan brown bear, american civil war, carpenter's square, haberdashery store, hundred years' war, military volunteer, pacific silver fir, russo-japanese war, tender loving care

19 letters:
american black bear, automotive engineer, efficiency engineer, elasticity of shear, electrical engineer, european silver fir, franco-prussian war, mechanical engineer

20 letters:
california white fir, pinion and ring gear, vestibule of the ear

21 letters:
aeronautical engineer, book of common prayer, building supply store, delusions of grandeur, french and indian war, inspection and repair

22 letters:
battle of marston moor, metallurgical engineer, privilege of the floor

31 letters:
reserve officers training corps