2 syllables:
close a, cosa, glosa, gosa, grossa, kosa, llosa, loasa, posa, prosa, rossa, sosa, sposa

3 syllables:
acosa, aftosa, alosa, alrosa, arosa, barbosa, bullosa, canosa, canossa, carcosa, cardosa, cimosa, darosa, denosa, derosa, diosa, dirosa, dyosa, esposa, fibrosa, filosa, flindosa, formosa, frondosa, gangosa, hermosa, icosa, jambosa, jocosa, karosa, larosa, lechosa, limosa, linosa, lobosa, lycosa, makossa, margosa, melosa, mendosa, mimosa, mucosa, mucosae, nervosa, nodosa, pedrosa, pilosa, qualcosa, raposa, reposa, reynosa, rugosa, samosa, sentosa, serosa, spinosa, squamosa, stoklosa, sub-rosa, tolosa, tryphosa, urbosa, venosa, ventosa, villosa, viscosa

4 syllables:
acetosa, alamosa, amargosa, amorosa, annulosa, aporosa, arenosa, barbarosa, buddhaghosa, caseosa, cellulosa, cimarosa, delarosa, dolorosa, emarosa, eti-osa, flexuosa, frecciarossa, fruticosa, gaseosa, generosa, gloriosa, glutinosa, graciosa, grandiosa, granulosa, hinojosa, keratosa, lacrimosa, mafiosa, mariposa, nebulosa, nemorosa, pars nervosa, pellerossa, penalosa, pigmentosa, ponderosa, preciosa, ramaphosa, rebordosa, saragosa, saragossa, scabiosa, siliquosa, speciosa, submucosa, subserosa, torregrossa, tuberosa, vallombrosa, verderosa, verrucosa, virtuosa, wauwatosa, zaragosa

5 syllables:
genus mimosa, porcelanosa, prairie mimosa, religiosa, reticulosa, serpiginosa, ventanarosa, vesiculosa, villahermosa, villajoyosa

6 syllables:
cyril ramaphosa, gabriel barbosa

7 syllables:
anthony franciosa, enrico casarosa, ferrari testarossa, republic of formosa

8 syllables:
anorexia nervosa, mitragyna speciosa

9 syllables:
antonio villaraigosa