Costumes rhymes with:
maktoums, tombs, toombs, assumes, bloom's, blooms, boom's, booms, brooms, consumes, coombs, coomes, crooms, dooms, exhumes, flumes, fumes, groomes, grooms, humes, looms, maktoums, parfums, perfumes, plumes, presumes, resumes, room's, rooms, tombs, toombs, zooms
Costumes sounds like:
cadence, cadences, cadmus, cascading, casting, castings, castonguay, catanese, catatonic, cattanach, cautioning, cautions, ceding, chattanooga, chattanooga's, chattanuga, chatting, cheating, chestang, chetniks, chiding, chitinous, citations, citing, coasting, coating, coatings, codding, coding, coexistence, coexisting, costanza, costanzo, costing, cotton's, cottons, cuauhtemoc, custodians, customize, customizes, customs, cuteness, cutting, cuttings