Center letter: u
Outer letter: a b g i l n
Answers (44):
  bilingual
  annual
  annul
  annuli
  annulling
  biannual
  bubba
  bubbling
  bugging
  bugling
  bulb
  bulging
  bull
  bung
  bungling
  gauging
  glug
  glugging
  gluing
  gulag
  gull
  gulling
  gunning
  iguana
  linguini
  luau
  lubing
  lugging
  luging
  lull
  lulling
  lulu
  luna
  lung
  lunging
  lunula
  nubbin
  null
  ulna
  unbag
  unbagging
  unban
  unbanning
  unilingual