Here's what rhymes with certainment.
                        
                        
                    
                                attainment  arraignment  ascertainment  obtainment  detainment  edutainment  ordainment  entertainment  containment  entrainment  infotainment  Words that almost rhyme with certainment
payment  basement  pavement  subbasement  patient  statement  arrangement  placement  abatement  curtailment  raiment  abasement  plainchant  tamest  urbanest  adjacent  latent  vacant  amazement  claimant  nascent  repayment  blatant  derangement  faintest  vagrant  basest  debasement  effacement  plainest  entailment  overstatement  derailment  palest  defacement  degassed  sanest  vainest  chastest  gamest  fainest  engagement  latest  replacement  impatient  platelet  reagent  flagrant  fragrant  rearrangement  safest  assailant  bracelet  bravest  estrangement  divalent  emplacement  prepayment  restatement  wavefront  misstatement  nonpayment  shamefaced  escapement  lakefront  sadist  cadenced  disarrangement  encasement  prearrangement  quaintest  underpayment  opaqued  staidest  sedatest  halest  inanest  greatest  displacement  affidavit  supernatant  complainant  covalent  enslavement  understatement  intranet  inhalant  misplacement  straightest  anapest  nonadjacent  humanest  insanest  unchastest  complacent  disengagement  reinstatement  complaisant  unsafest