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