1 syllable:
bloom, blue&me, blum, blume, boom, boomm, broom, broome, brume, bthoom, choom, cloom, coomb, coombe, croom, crume, cu mm, dhoom, doom, droom, flume, froom, fume, gloom, glume, groom, groome, grume, heaume, hume, krume, kume, loom, neume, plume, pneum, reaume, rewme, rheaume, rheum, rhumb, rhume, room, roome, sh-boom, shoom, shroom, shtoom, sloom, spoom, spume, stoom, stroom, suhm, tomb, tombe, vroom, vroomm, whom, womb, zoom

2 syllables:
abloom, absume, addoom, agrume, artume, assume, backroom, back room, ballroom, barroom, bath-room, bathroom, batoum, bedroom, bitume, boardroom, box-room, boxroom, bridegroom, broadloom, bunkroom, busboom, by-room, cardroom, changeroom, chatroom, chat room, checkroom, child's room, classroom, clean-room, cleanroom, clean room, cloakroom, clubroom, coatroom, consume, cookroom, cornblume, costume, courtroom, coutume, darkbloom, darkroom, dayroom, dead room, death-doom, deblum, deplume, despume, displume, dorm room, drawloom, effume, embloom, emplume, enclume, engloom, entomb, enwomb, exhume, feldblum, fireroom, front room, game room, green-broom, greenroom, green broom, grillroom, guardroom, guestroom, gunroom, gun room, handloom, headroom, heirloom, herdgroom, homeroom, houseroom, icewm, illume, inhume, insume, intomb, jib-boom, jibboom, ka-boom, kaboom, keurboom, khartoum, laboum, laplume, legroom, legum, legume, lightroom, lindbloom, lunchroom, macroom, mailroom, maktoum, maybloom, mcbroom, men's room, mf doom, mtume, mudroom, mydoom, naboom, natsume, newsroom, okoume, outroom, pantoum, parfum, parfume, perfume, playroom, poolroom, pressroom, presume, pump room, push broom, raceroom, rebloom, rec room, reillume, relume, restroom, resume, reume, roseboom, royaume, salesroom, salume, schoolroom, scotch broom, sea room, showroom, sickroom, simoom, spekboom, staffroom, stateroom, steam room, stillroom, still room, stockroom, stock room, storeroom, strongroom, subsume, sukhum, sumoom, sunroom, sweat room, tap-room, taproom, tearoom, test room, toolroom, transhume, transume, ubume, unplume, untomb, varoom, wardroom, wareroom, warkloom, washroom, wash room, weightroom, whiskbroom, white broom, white room, witch broom, workroom

3 syllables:
a400m, after-room, alumbloom, ante-room, anteroom, apostume, baby's room, baby-boom, baby boom, badaboom, billiard room, boiler-room, breathing room, butcher's broom, carpet loom, cfu-m, coffeeroom, common-room, common broom, common room, control room, corniplume, cutting room, daremblum, desert plume, dining-room, dining room, disentomb, disinhume, disselboom, drawing-room, drawing room, dressing-room, dressing room, elbow-room, elbowroom, elbow room, engine room, figure loom, filoplume, foredoom, furnace room, georgia groome, groovyroom, hecatomb, hotel room, impostume, introsume, isohume, ladies' room, lecture room, legalzoom, living-room, livingroom, living room, locker-room, lockerroom, locker room, low-warp-loom, lumber-room, lumber room, messroom, morning room, motel room, nom de plume, nutriboom, overgloom, pernille blume, petalum, potchefstroom, powder room, power loom, re-assume, reading room, reassume, ringelblume, rosenbloom, rosenblum, rosenboom, rozeboom, saleroom, scarlet plume, seating room, semiplume, sewing room, shipping room, shower room, silverboom, sitting-room, sitting room, sleeping room, smoking room, sonic boom, sonnenblume, spanish broom, standing room, storage room, testing room, tiring-room, tv room, vandenboom, wagenboom, waiting room, weaver's broom, womb-to-tomb, yubitsume

4 syllables:
ame-no-uzume, artist's workroom, bathing costume, brodifacoum, chaparral broom, conference room, electroboom, family room, google classroom, hospital room, indigo broom, kemonozume, master bedroom, microphone boom, monster musume, overconsume, reception room, recovery room, s1850m, swimming costume, the viper room, weeping tree broom, white spanish broom, withdrawing-room, withdrawing room

5 syllables:
5.8x42mm, adobe lightroom, dormitory room, dynamic headroom, emergency room, masquerade costume, nehruviandoom, operating room, recreation room, television room

6 syllables:
academic costume

7 syllables:
assassination classroom