Center letter: o
Outer letter: d h i m n t
Answers (36):
  midmonth
  dhoti
  dino
  ditto
  dodo
  dominion
  domino
  doom
  doth
  hominid
  hominoid
  hood
  hoodoo
  hoot
  idiom
  idiot
  into
  minion
  mondo
  mono
  month
  mood
  moon
  moot
  moth
  motion
  motto
  noon
  notion
  omit
  onion
  onto
  tomtit
  toon
  toot
  tooth