1 syllable:
'em, 'm, -some, bd-rom, bluhm, brum, brumm, bum, chum, clum, cm sm, come, comme, crum, crumb, crumm, csc ssm, cum, ddrum, druim, drum, drumm, dslam, dum, dumb, dumm, dzbb-am, dzrj-am, frum, fsk im, gd-rom, glum, gmbh, gmm sm, grum, gthumb, gum, gumm, hb gam, hm, hmm, hp tim, hrtem, hum, humm, jlc csm, jpcg dimm, jstars gsm, khnum, klumb, krum, krumm, krumme, kumm, lum, lumb, lumm, lumme, lv sem, maam, mp gam, msd sm, msn im, mum, mumm, mumme, nccam, nd tem, ngcam, ns qam, numb, pflum, phlem, phleme, plum, plumb, pps sm, rhomb, rs tim, rum, schem, schrum, schtum, schum, schumm, scrum, scum, scumm, shrum, shtum, shum, skrim, slum, smd imb, smram, some, spf dbim, sp tcim, std ssm, strum, stum, stumm, stumme, sum, summe, swum, them, thrum, thum, thumb, thumm, tp fem, tshombe, um, umm, v-comb, vl-srsam, xrsam, yum, -derm, -sperm, berm, chirm, churme, derm-, ferm, ferme, firm, firme, germ, germe, herm, herme, hurm, mp erm, phirm, scherm, schirm, sherm, sperm, squirm, sturm, tc erm, term, terme, therm, therm-, therme, thurm, verme, worm, wurm

2 syllables:
aksum, alum, ancrum, bass drum, baucum, bay rum, beach plum, become, benumb, bethumb, bithumb, black gum, blue gum, boyum, brake drum, branscome, breadcrumb, cancrum, carum, checksum, columb, date plum, deblum, dishyum, djarum, encom, exum, faiyum, first-come, freedumb, ghost gum, goodrum, goose plum, green thumb, guthrum, herefrom, hog plum, hohum, hop-thumb, how come, humdrum, ikwum, income, keep mum, kim bum, larum, lump-sum, marum, mccrum, mccrumb, narum, neu-ulm, noucome, outcome, pileum, plethrum, pond scum, red drum, red gum, rose gum, sharum, side drum, snare drum, snow gum, steak-umm, steel drum, stepmom, striped drum, succumb, swamp gum, sweet gum, tear-thumb, tecum, therefrom, tom thumb, unplumb, wellcome, wherefrom, wild plum, yab-yum, yum-yum, yumyum, affirm, affirme, afirm, bandwurm, beard worm, bildschirm, bookworm, caseworm, confirm, confirme, cutworm, degerm, deperm, devshirme, dew worm, earthworm, fireworm, fishworm, flukeworm, full-term, full term, gapeworm, half-term, heartworm, hold firm, horseworm, inchworm, inerm, inerme, infirm, inserm, ismrm, kirchturm, landsturm, late-term, law firm, leuchtturm, long-term, longterm, maltworm, midterm, near-term, nonterm, obfirm, ohrwurm, oosperm, outterm, pileworm, red worm, rootworm, roseworm, russwurm, schneesturm, school term, seatworm, short-term, shortterm, stand firm, tapeworm, tongueworm, tongue worm, tubeworm, unfirm, volkssturm, wheatworm, wheat germ, wireworm, woodworm, xterm, zoosperm

3 syllables:
adnexum, amarum, amphicome, august plum, barathrum, beetlebum, bongo drum, bubble gum, bungarum, cherry plum, chewing gum, cider gum, cocoa plum, coco plum, common plum, congo gum, damson plum, deaf-and-dumb, direct sum, disbecome, flooded gum, labarum, manna gum, mesquite gum, metal drum, misbecome, mishawum, moxie plum, natal plum, net income, no-see-um, norodom, obesum, overcome, physarum, podarthrum, pyrethrum, river gum, rule-of-thumb, rule of thumb, saccharum, sisarum, sour gum, spirit gum, spotted gum, tartarum, tax income, tenor drum, tidy sum, time to come, unbecome, unbenumb, vector sum, water gum, zero-sum, androderm, angleworm, army worm, arthroderm, aussichtsturm, bioherm, biotherm, bladder worm, business firm, chrysosperm, counterterm, decatherm, diasyrm, disaffirm, disconfirm, ectotherm, endoderm, endosperm, endotherm, epiderm, episperm, estraderm, eurytherm, exoderm, exotherm, fishing worm, geotherm, guinea worm, gymnosperm, haematherm, hematherm, homotherm, hypoderm, incoterm, isotherm, lidoderm, longer-term, major term, megaderm, megatherm, mesoderm, mesosperm, mesotherm, messeturm, microtherm, middle term, minor term, misaffirm, monosperm, nicoderm, opentherm, pachyderm, peanut worm, periderm, perisperm, phelloderm, pickleworm, placoderm, pododerm, podosperm, prison term, psorosperm, pteridosperm, railroad worm, reaffirm, reconfirm, regenschirm, regenwurm, remain firm, rhodosperm, ribbon worm, sarcoderm, scleroderm, service firm, spermoderm, spindleworm, stenoderm, stenotherm, tatzelwurm, trophoderm, trophosperm, velvet worm, zygosperm

4 syllables:
abomasum, arisarum, canada plum, carissa plum, chickasaw plum, dante exum, erucifrom, falciparum, forest red gum, glyoxysome, governor's plum, governor plum, granulosum, hedysarum, hop-o'-my-thumb, jamaica rum, japanese plum, marmalade plum, mountain swamp gum, pacific plum, peppermint gum, pigmentosum, principal sum, river red gum, senegal gum, sierra plum, sonora gum, stenotaphrum, the world to come, unearned income, accounting firm, angiosperm, annelid worm, army cutworm, brokerage firm, carry to term, consulting firm, echinoderm, electrotherm, erythra-derm, geoisotherm, heterotherm, homeotherm, homoiotherm, insurance firm, investment firm, isallotherm, malacoderm, measuring worm, medium-term, melanosperm, osteoderm, ostracoderm, poikilotherm, potato worm, proboscis worm, progymnosperm, publishing firm, removal firm, segmented worm, syphiloderm, tomato worm, vinegar worm

5 syllables:
alleghany plum, allegheny plum, eucalyptus gum, government income, madagascar plum, national income, personal income, tetrapharmacum, whatever may come, academic term, chordamesoderm, chordomesoderm, degree of a term, isobathytherm, isodrosotherm, isogeotherm, olympiaturm, parasitic worm, presidential term, securities firm

6 syllables:
american red plum, american sweet gum, disposable income, oleosaccharum, per capita income, intermediate-term

8 syllables:
universal basic income