Center letter: t
Outer letter: u a c h m p
Answers (30):
  matchup
  attach
  captcha
  catch
  catchup
  chat
  cutup
  hatch
  hath
  hatha
  hutch
  mahatma
  match
  matcha
  math
  mutt
  pact
  patch
  path
  phat
  putt
  tach
  tact
  tamp
  tapa
  taut
  that
  thatch
  thump
  tutu