Center letter: n
Outer letter: g i l m u z
Answers (40):
  muzzling
  unmuzzling
  gigging
  giggling
  gilling
  ginning
  glugging
  gluing
  gulling
  gumming
  gunning
  guzzling
  immunizing
  inning
  limn
  limning
  linguini
  lining
  lugging
  luging
  lulling
  lung
  lunging
  milling
  miming
  mingling
  mini
  minim
  minimizing
  minimum
  mining
  mugging
  mulling
  mung
  niggling
  null
  nuzzling
  zigging
  zing
  zinging