Center letter: r
Outer letter: a c i k m o
Answers (41):
  microcrack
  arco
  aria
  armor
  aroma
  carioca
  carom
  circa
  cirri
  coir
  cork
  crack
  cram
  crick
  croak
  croc
  croci
  crock
  crook
  karma
  karmic
  korma
  macro
  maraca
  mark
  marm
  micro
  mirror
  moor
  morocco
  okra
  orca
  rack
  rick
  roam
  roar
  rock
  rococo
  romcom
  rook
  room