Here's what rhymes with hippotamus.
Words that almost rhyme with hippotamus
exogenous eponymous motionless boastfulness emotionless wholesomeness loathsomeness lonesomeness soullessness dolefulness woefulness hopelessness socialists homelessness copiousness postmistress ferociousness soulfulness toastmistress atrociousness proteolysis chauvinists precociousness ufologists globalists unwholesomeness