Center letter: o
Outer letter: c g i n u v
Answers (30):
  unconvincing
  cocci
  cocoon
  cocooning
  coin
  coining
  conic
  conning
  conniving
  convincing
  cooing
  going
  gong
  gonging
  goon
  gouging
  icon
  iconic
  invoicing
  ionic
  noggin
  nonunion
  noon
  noun
  nuncio
  ongoing
  onion
  union
  voguing
  voicing