Center letter: t
Outer letter: d g h n o u
Answers (31):
  doughnut
  donut
  doth
  dugout
  goth
  gout
  hoot
  hotdog
  hunt
  nought
  onto
  ought
  outdo
  outgo
  outgun
  outthought
  thong
  thou
  though
  thought
  thud
  thug
  tong
  toon
  toot
  tooth
  tough
  tout
  tutu
  unthought
  unto