Center letter: a
Outer letter: c d e i n y
Answers (61):
  cyanide
  acacia
  acai
  accede
  acceded
  aced
  acid
  acidic
  acidy
  acne
  added
  addend
  addenda
  adenine
  aide
  aided
  caddie
  caddied
  caddy
  cadence
  cancan
  candid
  candidacy
  candied
  candy
  cane
  caned
  canid
  canine
  canna
  canned
  canny
  cayenne
  cicada
  cyan
  daddy
  dance
  danced
  dandy
  dead
  deaden
  deadened
  deadeye
  dean
  decade
  decadence
  decay
  decayed
  dyad
  ennead
  idea
  inane
  indica
  indicia
  naan
  nada
  naiad
  nana
  nannied
  nanny
  niacin