Center letter: e
Outer letter: f k l m n o
Answers (30):
  menfolk
  feel
  fell
  felon
  femme
  fennel
  flee
  floe
  keel
  keen
  kennel
  keno
  knee
  kneel
  knell
  leek
  lemon
  lone
  meek
  melee
  melon
  meme
  memo
  mole
  nene
  neon
  noel
  none
  oleo
  omen