4 letters:
corm, dorm, form, norm, orme, warm

5 letters:
-form, dorme, enorm, forme, horme, norme, scorm, slorm, storm, swarm, torme, xform

6 letters:
aswarm, biform, deform, efform, enform, enorme, inform, reform, rewarm, t-norm, unform, unwarm

7 letters:
aciform, aliform, ausform, bestorm, by-form, deforme, deiform, difform, informe, isoform, jotform, lauwarm, misform, oriform, outform, oviform, perform, pliform, preform, proform, re-form, schwarm, t-storm, triform, uniform, upswarm, webform

8 letters:
acneform, aeriform, age norm, alestorm, ansiform, aquiform, arciform, arkstorm, art form, auriform, benidorm, boniform, boviform, ciliform, cineform, coliform, conforme, coniform, cubiform, cuniform, difforme, ensiform, equiform, fabiform, feliform, ficiform, filiform, flexform, freeform, funiform, fusiform, gasiform, geostorm, gruiform, haloform, hamiform, homiform, iodoform, janiform, juliform, kaliform, landform, lifeform, luciform, lukewarm, luniform, lupiform, lyriform, maniform, moriform, muciform, muriform, napiform, nariform, nasiform, natiform, nuciform, omniform, outstorm, paliform, pediform, perform', phpstorm, piliform, piniform, piriform, pisiform, planform, platform, poriform, pro-form, puriform, pyriform, rabiform, ramiform, raniform, raystorm, remiform, reniform, retiform, riziform, rotiform, rubiform, semiform, seminorm, setiform, slipform, soliform, sudiform, tax form, theiform, tubeform, tubiform, unciform, uncoform, uniforme, ursiform, utriform, variform, vasiform, veriform, waveform

9 letters:
aciniform, acneiform, adeniform, anguiform, axiniform, bacciform, barnstorm, blogswarm, bromoform, bulbiform, bulliform, bursiform, cactiform, cairngorm, calciform, capriform, cauliform, celliform, cheliform, chyliform, ciliiform, cirriform, claviform, colliform, cominform, cordiform, cordoform, corniform, costiform, cruciform, cteniform, cuneiform, curviform, cymbiform, dentiform, disciform, disinform, dolioform, duststorm, eruciform, falciform, fibriform, filiforme, firestorm, floriform, foveiform, free form, fundiform, fungiform, galeiform, galliform, gemmiform, graniform, guttiform, hailstorm, halestorm, hydriform, ice storm, inconform, lanciform, landstorm, larviform, leaf form, lentiform, leptiform, libriform, life form, ligniform, lindiform, lituiform, maelstorm, mammiform, microform, misinform, misreform, mitriform, montiform, multiform, mummiform, musciform, myrtiform, nautiform, nitroform, nummiform, oculiform, ovaliform, palpiform, pappiform, peltiform, penniform, perciform, pileiform, pinniform, pisciform, planiform, plattform, plexiform, pre-storm, rainstorm, ralliform, restiform, ruiniform, sacciform, salpiform, sandstorm, scapiform, scobiform, scopiform, scoriform, scutiform, selliform, septiform, serriform, snowstorm, soleiform, spiciform, spiniform, stipiform, styliform, sulciform, take form, tauriform, tectiform, terraform, transform, turdiform, unciforme, unconform, unguiform, urceiform, valviform, vergiform, vermiform, villiform, vitriform, vulviform, wave form, whereform, wildstorm, windstorm, word form

10 letters:
actiniform, aculeiform, amentiform, amoebiform, anginiform, anseriform, araneiform, arboriform, ascidiform, baculiform, bloodstorm, botuliform, bound form, brainstorm, brianstorm, bufoniform, calceiform, calyciform, cancriform, caniniform, chloroform, choreiform, claim form, clypeiform, conchiform, coroniform, coryneform, cotyliform, cribriform, cruciforme, cuculiform, cucumiform, cultriform, cumuliform, cupuliform, cyathiform, dendriform, digitiform, disuniform, dust-storm, dust storm, elytriform, emboliform, etheriform, filariform, fluoroform, funiliform, funnelform, gangliform, gastronorm, ginglyform, glandiform, humaniform, hydatiform, lageniform, letterform, lightstorm, limaciform, line storm, linguiform, maidenform, malleiform, medusiform, molariform, monadiform, moniliform, motorstorm, noisestorm, nonuniform, nucleiform, obpyriform, order form, ostreiform, outperform, overinform, pateriform, petaliform, phylliform, poculiform, polypiform, preconform, proteiform, pumiciform, punctiform, quadriform, racemiform, radiciform, raduliform, resiniform, rostriform, saliniform, salverform, samariform, scrotiform, scyphiform, securiform, somatoform, spathiform, spongiform, springform, squaliform, squamiform, stelliform, stilliform, stratiform, strigiform, strumiform, subuliform, tabetiform, technivorm, tetaniform, thermoform, tubuliform, umbiliform, vaporiform, variciform, verse form, ypsiliform

11 letters:
aciculiform, acinaciform, acinetiform, aluminiform, alveoliform, ampulliform, andrew form, antenniform, antheriform, asbestiform, bacilliform, basaltiform, blamestrorm, branchiform, bulletstorm, calathiform, calcariform, campaniform, capilliform, castlestorm, cerebriform, chancriform, change form, chloroforme, choleriform, columbiform, columniform, coraciiform, coralliform, corticiform, corymbiform, crateriform, cypriniform, cypseliform, diversiform, dolabriform, drepaniform, electroform, falconiform, fistuliform, ganglioform, granitiform, granuliform, harengiform, herpetiform, isopodiform, kidney-form, lamelliform, land-reform, land reform, laniariform, licheniform, mamilliform, maxilliform, metalliform, muscariform, overperform, ovopyriform, pampiniform, panduriform, papilliform, passeriform, patelliform, pectiniform, plumiliform, plural form, pustuliform, radiatiform, retransform, sagittiform, sandaliform, scalariform, scalpriform, scombriform, siliqyiform, sonata form, spiculiform, stipitiform, subpyriform, trapeziform, umbelliform, vacciniform, varioliform, verruciform, z-transform, zeolitiform, zosteriform

12 letters:
amianthiform, amygdaliform, anguilliform, beeldenstorm, cocleariform, cylindriform, ectocuniform, embryoniform, entocuniform, epileptiform, equisetiform, extractiform, fibrilliform, flabelliform, flagelliform, fungilliform, gelatiniform, hydatidiform, lachrymiform, lebensreform, lumbriciform, mammilliform, membraniform, mesocuniform, meteor swarm, morbilliform, neuralgiform, operculiform, paraboliform, pelecaniform, placentiform, plataleiform, psittaciform, rostelliform, scutelliform, serpentiform, silver storm, stalactiform, stalactoform, strobiliform, thunderstorm, underperform, vesiculiform

13 letters:
acetabuliform, adipoceriform, ambulacriform, apoplectiform, campaniliform, citation form, cochleariform, columelliform, crossplatform, dress uniform, entocuneiform, hyperboliform, madreporiform, mandibuliform, mesocuneiform, multiplatform, penicilliform, semipenniform, singular form, strombuliform, tentaculiform, trichiuriform, umbraculiform, varicelliform, violent storm

14 letters:
aspergilliform, combining form, cross-platform, electric storm, hippocrepiform, labyrinthiform, magnetic storm, multi-platform, proboscidiform, salamandriform, scarlatiniform, space platform, stalactitiform, telegraph form

15 letters:
cook up a storm, hypocrateriform, infundibuliform, nitrochloroform, puzzle-platform, terebratuliform

16 letters:
application form, electrical storm, military uniform, nitro-chloroform, schizophreniform, weapons platform

17 letters:
drilling platform

18 letters:
political platform

19 letters:
heroes of the storm

21 letters:
google cloud platform

22 letters:
operation desert storm

3 letters:
arm

4 letters:
farm, worm, germ, firm, term, harm

5 letters:
alarm, smarm, sperm, therm, rearm, charm, unarm

6 letters:
unfirm, affirm, squirm, disarm, infirm, re-arm

7 letters:
confirm, forearm, becharm

8 letters:
underarm, reaffirm, tone arm, dew worm, law firm, endoderm, episperm, isotherm, mesoderm, red worm, side arm

9 letters:
tree farm, army worm, reconfirm, long-term, full term, full-term, hold firm, home-farm, small-arm, stud farm, wiper arm

10 letters:
fire alarm, beard worm, minor term, short-term, rocker arm, funny farm, truck farm, wheat germ, major term, dairy farm, pickup arm, schoolmarm, stand firm, strong-arm

11 letters:
tongue worm, middle term, smoke alarm, ribbon worm, guinea worm, cattle farm, contact arm, peanut worm, potato worm, prison farm, prison term, remain firm, school term, sewage farm, tomato worm, velvet worm, writing arm

12 letters:
buy the farm, bladder worm, annelid worm, fishing worm, removal firm, service firm, straight-arm, vinegar worm

13 letters:
burglar alarm, academic term, business firm, carry to term, railroad worm

14 letters:
brokerage firm, measuring worm, chordamesoderm, chordomesoderm, insurance firm, parasitic worm, proboscis worm, segmented worm

15 letters:
collective farm, accounting firm, consulting firm, good luck charm, investment firm, publishing firm, securities firm

16 letters:
degree of a term

17 letters:
presidential term