Here's what rhymes with flappable.
                        
                        
                    
                                unflappable  Words that almost rhyme with flappable
addible  capital  sagittal  detachable  compatible  incompatible  nondetachable  affable  flammable  laughable  animal  rational  palpable  fallible  cannibal  passable  verapamil  blamable  chasuble  graspable  frangible  satiable  savable  national  actual  radical  valuable  casual  tangible  irrational  taxable  adaptable  fractional  mandible  axonal  clavicle  inflammable  tractable  collapsible  bankable  cantabile  fanciable  practical  diagonal  maximal  impassable  implacable  infallible  factional  impalpable  cantonal  madrigal  impassible  nonflammable  attractable  declarable  invaluable  hexagonal  intangible  intractable  octagonal  expandable  merchantable  retractable  grammatical  impractical  lnternational  supranational  semiannual  unpractical  nontaxable  international  multinational  transnational  understandable  interactional  transactional  ungrammatical