Center letter: m
Outer letter: n p u d e l
Answers (40):
  pendulum
  deem
  deemed
  dumdum
  dump
  dumped
  emend
  emended
  lumen
  lump
  lumped
  meddle
  meddled
  meld
  melded
  melee
  meme
  memed
  mend
  mended
  menu
  muddle
  muddled
  mule
  mull
  mulled
  muumuu
  penmen
  peplum
  plenum
  plum
  plume
  plumed
  plump
  plumped
  pummel
  pummeled
  pump
  pumped
  umped