backyard vs quadrangle

backyard

noun
  • A yard to the rear of a house or similar residence. 

  • An area nearby to a country or other jurisdiction's legal boundaries, particularly an area in which the country feels it has an interest. 

  • A person's neighborhood, or an area nearby to a person's usual residence or place of work and where the person is likely to go. 

quadrangle

noun
  • A courtyard which is quadrangular. 

  • The buildings forming the border of such a courtyard. 

  • A geometric shape with four angles and four straight sides; a four-sided polygon. 

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