Center letter: r
Outer letter: a c i n o z
Answers (40):
  zirconia
  acorn
  arcana
  arco
  aria
  arnica
  cairn
  carioca
  carrion
  circa
  cirri
  coir
  corn
  corona
  crania
  croc
  croci
  croon
  czar
  czarina
  iron
  ironic
  narc
  narco
  noir
  nori
  ocarina
  orca
  orzo
  raccoon
  rain
  rancor
  rani
  razor
  razz
  ricin
  roan
  roar
  rococo
  zircon