Center letter: a
Outer letter: e h i n p y
Answers (26):
  epiphany
  apian
  apnea
  happen
  happy
  heap
  henna
  hiya
  hyena
  inane
  naan
  nana
  nanny
  nape
  neap
  paean
  pain
  pane
  panini
  papa
  papaya
  pappy
  payee
  peahen
  yappy
  yeah