Here's what rhymes with gainsayin.
                        
                        
                    
                                sayin  been  skin  sin  thin  win  min  tin  chin  kin  pin  spin  bin  din  fin  gin  lin  syn  yin  cine  hin  kine  shin  vin  jinn  djinn  therein  twin  akin  grin  herein  quin  shebeen  within  begin  wherein  violin  chagrin  tryin  bearskin  condign  journeymen  porcine  underpin  pinyin  mandolin  bogeymen  boogeymen  Words that almost rhyme with gainsayin
him  thing  king  ring  sing  wing  dim  limb  rim  swim  swing  hymn  slim  fling  gym  meme  sling  sting  whim  ling  ning  ping  skim  ting  tyme  wring  ching  ding  ming  sim  vim  shim  limn  zing  sousing  bring  spring  string  grim  cling  trim  brim  prim  bling  scrim  mewling  scything  sporing  rousting  moussing  anything  upswing  queering  gawping  everything  synonym  pseudonym  quicklime  antonym  prelim  texting  kibbutzim  huzzahing  dybbukim  kiln  villein