Here's what rhymes with postmenstruation.
                        
                        
                    
                                menstruation  nation  aeration  relation  situation  creation  formation  duration  location  station  variation  exploration  rotation  salvation  valuation  mutation  probation  starvation  toleration  donation  oration  dilation  elation  infatuation  legation  ligation  palpation  education  operation  application  explanation  generation  evaluation  foundation  imagination  preparation  radiation  separation  admiration  declaration  deviation  elevation  exploitation  inflation  inspiration  liberation  motivation  obligation  sensation  taxation  violation  agitation  allocation  alteration  aspiration  decoration  delegation  estimation  fixation  installation  irrigation  irritation  medication  meditation  notation  plantation  saturation  temptation  vacation  vegetation  vibration  affiliation  approbation  attenuation  aviation  causation  cessation  derivation  dilatation  expiration  fabrication  federation  filtration  graduation  habitation  incarnation  maturation  mediation  moderation  modulation  narration  negation  validation  veneration  vocation  aberration  adoration  allegation  appellation  automation  citation  damnation  exaltation  exhortation  exportation  fibrillation  gestation  hydration  inauguration  intonation  iteration  masturbation  perforation  reparation  sedation  stagnation  summation  ulceration  usurpation  information  population  interpretation  association  circulation  corporation  investigation  observation  occupation  publication  reputation  translation  activation  adaptation  appreciation  correlation  demonstration  expectation  indication  innovation  invitation  isolation  limitation  migration  preservation  realization  restoration  revelation  stimulation  transportation  acceleration  alienation  celebration  consultation  deformation  degradation  destination  dissertation  domination  excitation  hesitation  illumination  imitation  implication  incorporation  inflammation  initiation  manipulation  navigation  nomination  penetration  propagation  quotation  recreation  reservation  respiration  segregation  simulation  speculation  termination  ventilation  accusation  affirmation  aggregation  animation  authorization  dedication  deliberation  deprivation  desolation  desperation  dislocation  dissipation  distillation  elaboration  emigration  evaporation  exaggeration  excavation  fascination  importation  incubation  infiltration  insulation  irradiation  litigation  mobilization  ordination  oscillation  polarization  realisation  reformation  replication  retaliation  retardation  abbreviation  affectation  alternation  amputation  bifurcation  castration  conciliation  constellation  consternation  constipation  coronation  delineation  demarcation  deportation  deputation  devaluation  divination  duplication  elongation  elucidation  emulation  enumeration  eradication  escalation  exclamation  fertilization  fluctuation  germination  implantation  imputation  inactivation  inhalation  innervation  inoculation  interpolation  interrogation  intimation  invocation  ovulation  perspiration  perturbation  provocation  punctuation  recitation  refutation  relocation  renovation  repudiation  revocation  sanitation  stipulation  subjugation  vindication  visitation  administration  combination  consideration  examination  civilization  conversation  cooperation  integration  legislation  presentation  regulation  transformation  configuration  conservation  cultivation  formulation  illustration  immigration  modification  orientation  appropriation  arbitration  assimilation  collaboration  computation  confirmation  consolidation  continuation  degeneration  depreciation  designation  deterioration  elimination  emancipation  frustration  inclination  indignation  manifestation  negotiation  oxidation  precipitation  proclamation  proliferation  reconciliation  regeneration  registration  relaxation  resignation  utilization  annexation  annihilation  assassination  calibration  certification  civilisation  compilation  complication  consolation  denomination  dissociation  evacuation  fermentation  generalization  humiliation  ionization  modernization  notification  remuneration  socialization  specialization  stabilization  subordination  transplantation  unification  verification  adjudication  authentication  cancellation  confederation  confiscation  conformation  connotation  consecration  consummation  culmination  dehydration  denunciation  devastation  dispensation  extermination  gravitation  hybridization  immunization  intimidation  liquidation  magnetization  prolongation  reclamation  regurgitation  renunciation  sterilization  urbanization  utilisation  vaccination  organization  communication  concentration  determination  participation  accumulation  calculation  compensation  differentiation  justification  organisation  accommodation  anticipation  approximation  condemnation  confrontation  congregation  coordination  rehabilitation  specification  amplification  articulation  coagulation  colonization  condensation  dissemination  globalization  intoxication  localization  multiplication  optimization  preoccupation  privatization  pronunciation  purification  ratification  sophistication  stratification  amalgamation  augmentation  capitulation  centralization  commendation  conflagration  crystallization  deregulation  instrumentation  intensification  magnification  mortification  nationalization  normalization  polymerization  refrigeration  resuscitation  sedimentation  segmentation  simplification  standardization  supplementation  visualization  classification  identification  representation  discrimination  implementation  characterization  contamination  contemplation  documentation  qualification  recommendation  clarification  disintegration  experimentation  fragmentation  gratification  industrialization  liberalization  signification  calcification  capitalization  categorization  decentralization  democratization  diversification  excommunication  hospitalization  ornamentation  personification  rationalization  synchronization  reorganization  argumentation  conceptualization  misrepresentation  quantification  Words that almost rhyme with postmenstruation
haven  basin  hasten  occasion  evasion  equation  invasion  persuasion  taken  pagan  shaken  bacon  laden  maiden  layman  laymen  shaman  patron  awaken  forsaken  straighten  salesman  mistaken  undertaken  statesman  contagion  overtaken  tradesmen