aviary vs prison

aviary

noun
  • A house, enclosure, large cage, or other place for keeping birds confined; a birdhouse. 

prison

noun
  • Any restrictive environment, such as a harsh academy or home. 

  • Confinement in prison. 

  • A place or institution where people are held against their will, especially for long-term confinement of those awaiting trial or convicted of serious crimes or otherwise considered undesirable by the government. 

verb
  • To imprison. 

How often have the words aviary and prison occurred in a corpus of books? (source: Google Ngram Viewer )