Center letter: e
Outer letter: a g i k n p
Answers (52):
  peaking
  agape
  ageing
  apnea
  egging
  eking
  engage
  engaging
  engine
  epee
  gage
  gape
  geek
  geeking
  gene
  genie
  genii
  inane
  innie
  keen
  keening
  keep
  keeping
  kepi
  knee
  kneeing
  nankeen
  nape
  neap
  nene
  nine
  ninepin
  paean
  page
  pane
  peak
  peeing
  peek
  peeking
  peen
  peep
  peeping
  pegging
  peke
  penne
  penning
  pepping
  pigpen
  pike
  pine
  pinkie
  pipe