Center letter: o
Outer letter: a d h n t u
Answers (29):
  handout
  anon
  auto
  dodo
  donut
  doodad
  doth
  dunno
  hood
  hoodoo
  hoot
  hound
  noon
  noun
  nunhood
  oath
  onto
  outdo
  tattoo
  thou
  toad
  toon
  toot
  tooth
  tout
  udon
  undo
  unhood
  unto