Here's what rhymes with opynyon.
                        
                        
                    
                                pinyon  Words that almost rhyme with opynyon
tighten  bison  beiden  lineman  linemen  titan  lion  widen  brighten  fireman  firemen  heighten  lichen  lighten  ripen  siren  hyphen  liken  scion  siphon  baryon  hymen  prion  syphon  whiten  cotyledon  liven  linesman  finespun  horizon  fibrin  frighten  thriven  bedizen  billycan  enlighten  enliven  dicotyledon  veniremen  funnyman  aphelion  dandelion  monocotyledon  perihelion