Here's what rhymes with rancourous.
                        
                        
                    
                                glamourous  Words that almost rhyme with rancourous
clueless  lulus  hulas  truelove  scrofulous  hallelujahs  mucous  mucus  coolness  lupus  newness  chukkas  houmous  houmus  units  useless  nuisance  ruthless  cubits  eunuchs  humus  rudeness  hubris  toothless  blueness  congruous  crudeness  lewdness  moonless  roofless  rootless  bootless  caduceus  muteness  cuteness  gullets  glumness  cutups  ulnas  tuneups  fruitless  prudence  mutants  acuteness  shrewdness  smoothness  aloofness  fluence  tulips  tumults  astuteness  avoirdupois  obtuseness  annuitants  coolants  humourless  intuits  juleps  mullets  sublets  manumits  bouffants  students  movements  amusements  foodstuffs  pursuance  imprudence  impudence  truants  canoeists  duellists  translucence  profuseness  spruceness  hirsuteness  pollutants  inducements  diffuseness  exiguous  resoluteness  abstruseness  improvements  jurisprudence  persecutions  absoluteness  dissoluteness  quadruplets  irresoluteness  disputants