Here's what rhymes with certissimum.
                        
                        
                    
                                Words that almost rhyme with certissimum
women  gingham  persimmon  linen  chignon  pinon  gentlewomen  serum  theorem  cecum  system  rhythm  victim  symptom  schism  fearsome  fetishism  besom  lyceum  criticism  kingdom  wisdom  prism  activism  cynicism  dictum  gypsum  scepticism  eroticism  pacifism  aphorism  holism  lyricism  winsome  witticism  chrism  sophism  feminism  heroism  mysticism  skepticism  terrorism  altruism  dualism  feudalism  pessimism  pilgrim  positivism  relativism  classicism  egoism  fatalism  logarithm  narcissism  elitism  hedonism  recidivism  stoicism  albinism  exoticism  solipsism  futurism  purism  solecism  tropism  algorithm  organism  socialism  despotism  journalism  liberalism  optimism  symbolism  barbarism  dynamism  ecosystem  embolism  empiricism  fanaticism  federalism  formalism  humanism  modernism  radicalism  rheumatism  catechism  collectivism  egotism  nihilism  paganism  paroxysm  separatism  anarchism  animism  behaviorism  chauvinism  euphemism  exorcism  favoritism  heathenism  hypnotism  legalism  mannerism  nepotism  ostracism  pauperism  plagiarism  revisionism  shamanism  archaism  botulism  cretinism  isomerism  mesmerism  negativism  racialism  synergism  specialism  tokenism  mechanism  capitalism  alcoholism  pluralism  determinism  naturalism  romanticism  unionism  dogmatism  evangelism  militarism  regionalism  secularism  agnosticism  aneurism  cataclysm  centralism  corporatism  eclecticism  parasitism  populism  scholasticism  voluntarism  abolitionism  automatism  exhibitionism  favouritism  neutralism  revivalism  syndicalism  anabolism  bimetallism  charlatanism  creationism  galvanism  hooliganism  invalidism  philistinism  metabolism  communism  imperialism  nationalism  patriotism  antagonism  materialism  magnetism  parallelism  pragmatism  rationalism  absolutism  cannibalism  consumerism  hyperthyroidism  hypothyroidism  paternalism  protectionism  astigmatism  commercialism  emotionalism  isolationism  monasticism  traditionalism  ecumenism  gradualism  impressionism  parochialism  perfectionism  proselytism  puritanism  adventurism  dilettantism  minimalism  monetarism  mongolism  neoclassicism  triumphalism  colonialism  conservatism  individualism  anachronism  bilingualism  postmodernism  republicanism  antisemitism  expansionism  factionalism  functionalism  mercantilism  provincialism  sectarianism  clericalism  expressionism  sectionalism  agrarianism  ventriloquism  professionalism  authoritarianism  industrialism  sensationalism  sentimentalism  evangelicalism  interventionism  somnambulism  colloquialism  servomechanism  unilateralism  fundamentalism  internationalism  utilitarianism  cosmopolitanism  egalitarianism  existentialism  intellectualism  microorganism  anticommunism  multilingualism  transsexualism  totalitarianism  constitutionalism  environmentalism  humanitarianism  antiquarianism  neocolonialism  electromagnetism  transcendentalism