Center letter: o
Outer letter: g i n t u w
Answers (56):
  outwitting
  going
  gong
  gonging
  goon
  gouging
  gout
  gown
  gowning
  ignition
  ingot
  into
  intoning
  intuition
  noggin
  nonunion
  noon
  noting
  notion
  noun
  ongoing
  onion
  onto
  outgo
  outgoing
  outgun
  outgunning
  outing
  outwit
  owing
  owning
  togging
  tong
  tonging
  tonguing
  toning
  toon
  toot
  tooting
  toting
  tout
  touting
  towing
  town
  tuition
  union
  unto
  unwon
  winnow
  winnowing
  wino
  wont
  wonton
  wooing
  woot
  wowing