Center letter: g
Outer letter: b i n p r u
Answers (56):
  burping
  upbringing
  binging
  binning
  bribing
  brig
  bring
  bringing
  brining
  bugging
  bung
  burg
  burning
  gibing
  gigging
  ginning
  grin
  grinning
  grip
  griping
  gripping
  grub
  grubbing
  gunning
  guru
  inning
  inuring
  inurning
  nigiri
  nipping
  pigging
  ping
  pinging
  pining
  pinning
  piping
  prig
  pruning
  punning
  purging
  purring
  ribbing
  rigging
  ring
  ringing
  ripping
  rubbing
  ruing
  ruining
  rung
  running
  unpinning
  unrig
  unrigging
  upping
  urging