Center letter: o
Outer letter: r w a b i n
Answers (45):
  rainbow
  anion
  anon
  arbor
  arborio
  arrow
  baboon
  baobab
  baron
  barrio
  barrow
  boar
  boba
  bobbin
  bonbon
  bonobo
  boob
  booboo
  boon
  boor
  born
  boron
  borrow
  bowwow
  brio
  brow
  brown
  inborn
  iron
  nabob
  narrow
  noir
  noob
  noon
  nori
  onion
  ribbon
  roan
  roar
  robin
  rowan
  warrior
  winnow
  wino
  worn