Here's what rhymes with welldefinable.
                        
                        
                    
                                definable  indefinable  undefinable  Words that almost rhyme with welldefinable
desirable  viable  sizable  sizeable  decidable  liable  excitable  assignable  likable  likeable  risible  liveable  deniable  reliable  advisable  undesirable  pliable  describable  survivable  undeniable  verifiable  inadvisable  realizable  indictable  ascribable  recyclable  certifiable  notifiable  climbable  rectifiable  unlikeable  unliveable  identifiable  justifiable  unreliable  indescribable  irreconcilable  libidinal  classifiable  cognizable  maniacal  reconcilable  analyzable  unverifiable  nonassignable  recognizable  unjustifiable  ammoniacal  demoniacal  unidentifiable  unrecognizable  monomaniacal