Center letter: l
Outer letter: d g i m n p
Answers (28):
  dimpling
  diddling
  dill
  giggling
  gild
  gilding
  gill
  gilling
  gliding
  idling
  limn
  limning
  limp
  limpid
  limping
  lining
  lipid
  lipping
  middling
  mild
  mill
  milling
  mingling
  niggling
  piddling
  piling
  pill
  pilling