Ostman rhymes with:
axtman, chestman, chrestman, christman, christmann, dustman, eastman, forstmann, gerstman, horstman, horstmann, justman, postman, westman
Ostman sounds like:
o'steen, octane, ogden, ossetian, osteen, osten, ostin, oxdon, oxidation, oxidyne, oxton