birdcage vs enclosure

birdcage

noun
  • A cage to keep pet or zoological specimen birds in. 

  • A game of chance played with dice; chuck-a-luck. 

enclosure

noun
  • An area, domain, or amount of something partially or entirely enclosed by barriers. 

  • The area of a convent, monastery, etc where access is restricted to community members. 

  • The act of separating and surrounding an area, domain, or amount of something with a barrier. 

  • The act of enclosing, i.e. the insertion or inclusion of an item in a letter or package. 

  • Something enclosed, i.e. inserted into a letter or similar package. 

  • The act of restricting access to ideas, works of art or technologies using patents or intellectual property laws. 

  • The post-feudal process of subdivision of common lands for individual ownership. 

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