Center letter: b
Outer letter: g i l m n o
Answers (55):
  blooming
  bill
  billing
  billion
  binging
  bingo
  binning
  blin
  bling
  blini
  blob
  blobbing
  blog
  blogging
  bloom
  bobbin
  bobbing
  bobbling
  bogging
  boggling
  boil
  boiling
  boing
  boll
  bolo
  bomb
  bombing
  bonbon
  bong
  bongo
  boning
  bonobo
  boob
  booboo
  booing
  boom
  booming
  boon
  gibbon
  gibing
  glib
  glob
  gobbling
  goblin
  imbibing
  limb
  limbo
  lobbing
  lobo
  mobbing
  nibbling
  nimbi
  noob
  obliging
  oblong