Center letter: h
Outer letter: m p t u a c
Answers (29):
  matchup
  attach
  captcha
  catch
  catchup
  champ
  chap
  chat
  chum
  chump
  chuppah
  hatch
  hath
  hatha
  hump
  humph
  hutch
  mahatma
  match
  matcha
  math
  much
  patch
  path
  phat
  tach
  that
  thatch
  thump