Costume rhymes with:
entomb, khartoum, maktoum, tomb, abloom, assume, bloom, blum, blume, boom, broom, broome, consume, croom, crume, deblum, doom, entomb, exhume, flume, fume, gloom, groom, groome, hume, kaboom, khartoum, kume, laplume, legroom, loom, maktoum, mcbroom, perfume, plume, presume, reassume, reaume, resume, rheaume, room, roome, suhm, tomb, vroom, whom, womb, zoom
Costume sounds like:
cadam, cadden, cadena, cadman, cadmium, caetano, castano, castanon, casteen, casten, castine, caston, catain, catania, catano, catena, catino, caton, catone, cattaneo, cattani, catton, catwoman, causation, cauthen, cauthon, caution, cawthon, caxton, cayton, cedeno, cessation, chadian, chastain, chasteen, chasten, chatham, chatman, chatmon, chattin, chatwin, chaudoin, cheatham, cheatum, cheetan, cheetham, chestman, cheston, chetwin, chittum, chutney, citation, cittadino, coatney, cogitation, cookston, costain, costano, costen, costin, coston, cotham, cotman, cotney, cottam, cotten, cottman, cottom, cotton, cottone, cowden, cudney, custodian, custom, cuttino, cydonia, cyhexatin