Mattress's rhymes with:
actress's, actresses, fortresses, waitresses, actress's, actresses, choruses, congress', congress's, congresses, cypress's, embarrasses, fortresses, gavras's, heiresses, irises, norris's, retroviruses, sampras's, virus's, waitresses, walruses
Mattress's sounds like:
madaras, madaris, madras, madres, madruga, manders, mandracchia, mandrake, mandresh, matarazzo, matarese, mathers, matra's, matriarch, matriarchy, matrice, matrices, matrix, matrix's, matrixes, matter's, matterease, matters, mattress, mattresses, matures, meaders, meadors, meanders, medarex, medaris, medders, medearis, medeiros, mederos, mediators, meinders, mentor's, mentors, metathorax, meteoric, meteors, meters, metres, metric, metrick, metrics, metro's, miniatures, miniaturize, modarressi, modrak, monitors, monterosso, montrose, montross, montrouis, moteurs, mother's, mothers, mothers', motor's, motorize, motors, motors', mudrick, mutters