4 letters:
belo, celo, delo, melo, velo

5 letters:
atelo, bello, cello, chelo, cielo, dello, duelo, gello, gwelo, jello, kello, mello, myelo, nello, pyelo, rello, sello, stelo, tello, telo-, thelo, vello, vuelo, yello, zello

6 letters:
abuelo, aiello, anello, anhelo, arello, bellow, cabelo, canelo, coelho, coello, cuello, dacelo, demelo, duello, fellow, hell-o, jell-o, kellow, mellow, modelo, niello, novelo, otello, pellow, pimelo, pomelo, pumelo, pyelo-, quello, ravelo, rebelo, robelo, scielo, sotelo, spello, stello, telloh, trello, yellow

7 letters:
808melo, agnello, amarelo, angello, appello, aquello, armello, augello, barbelo, barcelo, bilello, bonello, borello, botelho, botello, bunuelo, cabello, camello, capello, carello, carmelo, castelo, chabelo, colello, covello, curbelo, debello, demello, dibello, dicello, dilello, gamello, hengelo, jagello, karkelo, labello, lavello, livello, lobello, lorello, maiello, marcelo, mindelo, modello, monello, morello, mugello, novello, othello, pisello, ravello, rebello, revello, robello, rosello, sotello, strelow, tangelo, tirello, torello, trapelo, uccello, vangelo, vitello

8 letters:
arguello, bargello, borrello, brunello, cammello, cancello, cappello, cardello, cariello, carrello, castello, cervello, chipello, ciriello, coltello, condello, corbello, corsello, costello, coviello, crivello, dalbello, daniello, deangelo, destello, diangelo, eurovelo, fariello, fiorello, fratello, iannello, jagiello, mantello, marcello, martello, masiello, mondello, montello, ombrello, pennello, pirrello, porcello, prunello, puntello, rakomelo, rebellow, riviello, servello, sgabello, sorbello, sordello, spinello, stangelo, strehlow, torcello, unfellow, verdelho, vermelho, vitiello

9 letters:
albarello, antonello, azzarello, bedfellow, boitumelo, buentello, caldrello, cappiello, carabello, carangelo, caravello, chiarello, civitello, colangelo, donatello, funicello, ianniello, illangelo, leporello, maranello, marinello, matajuelo, mauriello, militello, mongiello, nardiello, oddfellow, orbetello, paisiello, perriello, pewfellow, pinarello, pisanello, pocatello, raffaello, rastrello, romanello, scarpello, scrivello, tomasello, torsiello, tuminello, zamarello

10 letters:
abbatiello, botshabelo, brocatello, campanello, campobello, ciccarello, cornicello, darcangelo, filippello, fratangelo, goodfellow, limoncello, longfellow, mandocello, manganello, marshmello, masaniello, mazzatello, montebello, monticello, muscarello, overmellow, parrinello, picariello, pirandello, piscitello, playfellow, ponticello, portabello, portobello, punchnello, ritornello, romaniello, ruggirello, sakartvelo, saltarello, santangelo, tamburello, terciopelo, tortorello, tumminello, vow-fellow, workfellow, yokefellow

11 letters:
alberobello, coachfellow, deep-yellow, femminiello, friggitello, hail-fellow, manganiello, marshmallow, marshmellow, mastrangelo, minichiello, pasquarello, pietrangelo, punchinello, rockafellow, santaniello, tortoriello, underfellow, violoncello, yoke-fellow

12 letters:
cartusciello, giovanniello, pasquariello, schoolfellow, stringfellow

13 letters:
canary-yellow, sulfur-yellow

14 letters:
crimson-yellow, frangokastello, sulphur-yellow

15 letters:
brownish-yellow

6 letters:
felloe

8 letters:
bordello