Center letter: n
Outer letter: e l o p t u
Answers (50):
  opulent
  entente
  lent
  lento
  lone
  loon
  lune
  lunette
  nene
  neon
  nettle
  noel
  none
  nonet
  noon
  nope
  note
  noun
  null
  onto
  open
  opponent
  peen
  peloton
  penne
  pent
  penult
  peon
  pollen
  pone
  pontoon
  potent
  punt
  teen
  tenet
  tenon
  tent
  tentpole
  tone
  tonne
  toon
  tune
  tuneup
  tunnel
  unlet
  unopen
  unpen
  unto
  untune
  upon