Here's what rhymes with castorum.
forum carom decorum quorum falciparum Words that almost rhyme with castorum
sporran foreign column solemn pollen warren slalom fallen befallen bottom boredom dorsum bonum possum stardom blossom mortem balsam sorghum opossum foursome gastronome problem condom drachm nostrum rostrum wampum flotsam thraldom thralldom quantum postpartum metronome cockscomb sugarplum microcosm macrocosm