Center letter: t
Outer letter: b h i n o r
Answers (47):
  inhibitor
  biotin
  birth
  bonito
  boot
  booth
  both
  broth
  hint
  hobbit
  hoot
  inhibit
  inhibition
  into
  intro
  ninth
  nitro
  north
  notion
  obit
  onto
  orbit
  ribbit
  riot
  robot
  root
  roti
  rotini
  rotor
  thin
  thorn
  throb
  tinhorn
  tint
  toon
  toot
  tooth
  tori
  torii
  torn
  toro
  tort
  tortoni
  trio
  triton
  trot
  troth