Here's what rhymes with knottedness.
                        
                        
                    
                                Words that almost rhyme with knottedness
heartedness  naughtiness  mawkishness  morbidness  haughtiness  soreness  balminess  hawkishness  goriness  snobbishness  heartsickness  waspishness  carsickness  downheartedness  suaveness  oxidants  exhaustiveness  kindheartedness  warmheartedness  bigheartedness  cognisance  hardheartedness  tenderheartedness  responsiveness  inconspicuous  recognisance  acknowledgments  acknowledgements  intoxicants  unresponsiveness  overconfidence  admonishments  exorbitance  garnishments  subcontinents  accomplishments