Here's what rhymes with firstborn.
                        
                        
                    
                                born  borne  torn  barn  darn  porn  tarn  corn  worn  horn  warn  yarn  adorn  morn  mourn  thorn  shorn  forborne  lorn  scorn  sworn  forlorn  unborn  reborn  outworn  stillborn  lowborn  waterborne  forewarn  lovelorn  peppercorn  timeworn  unworn  sweetcorn  careworn  forsworn  foresworn  unicorn  Words that almost rhyme with firstborn
charm  dorm  form  farm  warm  harm  storm  norm  forme  perform  alarm  forearm  psalm  swarm  disarm  deform  firearm  rearm  underarm  reform  inform  thunderstorm  outperform  preform  vermiform  yardarm  overarm  rewarm  conform  lukewarm  fusiform  nonfarm  multiform  schoolmarm  uniform  transform  cruciform  misinform  chloroform  cuneiform  nonuniform  don  dawn  bon  pawn  bonne  john  upon  non  drawn  gone  von  con  lawn  yon  hon  wan  baton  fawn  han  schon  spawn  yawn  khan  sawn  sonne  vpon  brawn  prawn  faun  gnawn  thereon  salon  swan  yuan  fagon  npon  operon  begone  chaperon  chiffon  hereupon  pecan  tenon  hereon  mastodon  predawn  autobahn  outdrawn  undergone  withdrawn  thereupon  foregone  positron  whereon  echelon  exon  octagon  redrawn  forgone  overdrawn  aileron  amazon  antiphon  heptagon  lasagne  upsilon  frogspawn  methadon  whereupon  polygon  automaton  denouement  pantheon  hexagon  paragon  pentagon  epsilon  tarragon  woebegone  leprechaun  neocon  trimaran  phenomenon  lexicon  marathon  carillon  cordovan  emoticon  rapprochement  pantechnicon