Center letter: o
Outer letter: a c k l n u
Answers (45):
  uncloak
  anon
  cacao
  callaloo
  cannon
  canola
  canon
  cloaca
  cloak
  clock
  clonk
  coal
  coca
  cock
  cocoa
  cocoon
  cola
  colcannon
  colon
  conk
  cook
  cool
  cuckoo
  knock
  knoll
  koala
  koan
  kola
  kook
  llano
  loan
  local
  lock
  loco
  loll
  look
  loon
  nock
  nonlocal
  nook
  noon
  noun
  uncock
  uncool
  unlock