Here's what rhymes with platonicism.
                        
                        
                    
                                schism  pacifism  journalism  prism  activism  cynicism  eroticism  anarchism  animism  aphorism  holism  mesmerism  chrism  sophism  mechanism  feminism  heroism  mysticism  terrorism  barbarism  dynamism  pessimism  positivism  classicism  dogmatism  egoism  narcissism  nihilism  paternalism  aneurism  elitism  exorcism  fetishism  lyricism  mannerism  nepotism  pauperism  recidivism  archaism  botulism  witticism  solecism  criticism  metabolism  organism  communism  socialism  antagonism  despotism  optimism  altruism  determinism  dualism  embolism  empiricism  fanaticism  formalism  magnetism  modernism  pragmatism  relativism  rheumatism  romanticism  scepticism  catechism  egotism  fatalism  militarism  paganism  regionalism  agnosticism  chauvinism  euphemism  heathenism  hedonism  ostracism  plagiarism  populism  shamanism  stoicism  albinism  automatism  exoticism  isomerism  negativism  racialism  solipsism  synergism  adventurism  anabolism  bimetallism  futurism  monetarism  mongolism  purism  specialism  tokenism  tropism  capitalism  nationalism  alcoholism  liberalism  pluralism  skepticism  symbolism  federalism  feudalism  humanism  naturalism  parallelism  radicalism  rationalism  unionism  anachronism  cannibalism  collectivism  evangelism  protectionism  separatism  astigmatism  behaviorism  commercialism  favoritism  hypnotism  legalism  mercantilism  monasticism  parasitism  provincialism  revisionism  traditionalism  voluntarism  abolitionism  favouritism  impressionism  neutralism  perfectionism  dilettantism  imperialism  patriotism  colonialism  conservatism  materialism  professionalism  absolutism  consumerism  postmodernism  republicanism  secularism  antisemitism  centralism  corporatism  eclecticism  emotionalism  expansionism  factionalism  functionalism  scholasticism  cretinism  ecumenism  gradualism  parochialism  proselytism  puritanism  revivalism  sectionalism  syndicalism  individualism  bilingualism  fundamentalism  isolationism  anticommunism  clericalism  exhibitionism  expressionism  authoritarianism  hyperthyroidism  hypothyroidism  industrialism  internationalism  totalitarianism  utilitarianism  egalitarianism  intellectualism  sectarianism  sensationalism  evangelicalism  interventionism  somnambulism  transcendentalism  constitutionalism  cosmopolitanism  existentialism  humanitarianism  microorganism  sentimentalism  electromagnetism  environmentalism  Words that almost rhyme with platonicism
vision  rhythm  arisen  risen  fission  mizzen  given  decision  division  listen  mission  prison  emission  incision  excision  riven  stiffen  rescission  position  addition  opposition  driven  edition  physician  algorithm  revision  forgiven  ignition  musician  omission  derision  fruition  magician  sedition  volition  envision  imprison  indecision  striven  audition  glisten  definition  commission  composition  permission  provision  television  transition  acquisition  admission  ambition  petition  precision  proposition  suspicion  abolition  ammunition  collision  deposition  exhibition  inhibition  intuition  nutrition  partition  politician  submission  clinician  imposition  remission  subdivision  supposition  tuition  admonition  apparition  attrition  demolition  erudition  apposition  dentition  logarithm  paroxysm  logician  manumission  rhetorician  ebullition  munition  prevision  condition  tradition  competition  transmission  disposition  expedition  repetition  supervision  coalition  cognition  exposition  prohibition  circumcision  preposition  requisition  technician  transposition  contrition  inquisition  intermission  patrician  rendition  cataclysm  disquisition  premonition  statistician  theoretician  dietitian  imprecision  tactician  recognition  decomposition  superstition  malnutrition  mathematician  predisposition  extradition  indisposition  interposition  precondition  presupposition  redefinition  superposition  electrician  academician  diagnostician  readmission  juxtaposition  obstetrician  pediatrician  superimposition  serum  theorem  cecum  system  wisdom  victim  fearsome  gingham  kingdom  symptom  dictum  gypsum  winsome  pilgrim  ecosystem