Here's what rhymes with louder.
                        
                        
                    
                                powder  chowder  prouder  Words that almost rhyme with louder
outer  outre  voucher  doubter  dauber  pouter  shouter  gouger  flouter  sloucher  stouter  scouter  our  hour  rounder  lounger  power  flower  tower  flour  founder  shower  sour  browser  bower  pounder  sounder  dour  flounder  trouser  cower  ouster  browner  howler  bounder  fouler  glower  prowler  downer  dowser  grounder  growler  mouser  sourer  drowsier  grouser  dourer  frowsier  counter  scour  bouncer  schnauzer  scrounger  jouster  mounter  scourer  trouncer  devour  empower  announcer  profounder  deflower  embower  unsounder  encounter  overpower  expounder  superpower  cauliflower  waterpower  cornflour  thundershower