Center letter: a
Outer letter: d i p t v y
Answers (22):
  adaptivity
  vapidity
  adapt
  avid
  avidity
  daddy
  data
  diva
  dyad
  paddy
  paid
  papa
  papaya
  pappy
  patty
  payday
  pita
  pitapat
  tapa
  tatty
  vapid
  yappy