Center letter: v
Outer letter: a c i l n o
Answers (28):
  convivial
  volcanic
  anvil
  avail
  avian
  cava
  cavil
  civic
  civil
  civilian
  lava
  naval
  nonvocal
  nova
  oval
  vain
  vanilla
  vanillin
  vial
  villa
  villain
  viol
  viola
  violin
  vocal
  vocalic
  voila
  volcano