Center letter: c
Outer letter: h m p t u a
Answers (24):
  matchup
  attach
  camp
  captcha
  catch
  catchup
  champ
  chap
  chat
  chum
  chump
  chuppah
  cuppa
  cutup
  hatch
  hutch
  match
  matcha
  much
  pact
  patch
  tach
  tact
  thatch