Center letter: o
Outer letter: d e n p u x
Answers (42):
  expound
  expounded
  dodo
  done
  donee
  donned
  dope
  doped
  doxed
  doxx
  doxxed
  dunno
  epode
  expo
  neon
  nodded
  node
  none
  noon
  nope
  noun
  odeon
  open
  opened
  oxen
  peon
  pond
  pone
  poop
  pooped
  pope
  popped
  pound
  pounded
  udon
  undo
  undone
  unopen
  unopened
  updo
  upon
  xenon