Center letter: r
Outer letter: b g i n p u
Answers (45):
  burping
  upbringing
  bribing
  brig
  bring
  bringing
  brining
  bruin
  burb
  burg
  burn
  burning
  burp
  burr
  grin
  grinning
  grip
  griping
  gripping
  grub
  grubbing
  guru
  inuring
  inurn
  inurning
  nigiri
  prig
  pruning
  purging
  purr
  purring
  ribbing
  rigging
  ring
  ringing
  ripping
  rubbing
  ruin
  ruing
  ruining
  rung
  running
  unrig
  unrigging
  urging