Center letter: a
Outer letter: c i n q t u
Answers (41):
  acquaint
  acacia
  acai
  acquit
  anti
  antic
  aqua
  aquanaut
  aquatic
  aquatint
  attain
  attic
  aunt
  cacti
  cancan
  canna
  cant
  cantata
  cantina
  cinquain
  incant
  intact
  naan
  nana
  natant
  niacin
  quaint
  quant
  quanta
  tacit
  tact
  tactic
  tactician
  taint
  tannic
  tannin
  taunt
  taut
  titan
  titanic
  tuna