choke pear vs pear tree

choke pear

noun
  • A kind of pear with a rough, astringent taste, difficult to swallow. 

  • A metal torture device to be inserted into the body, consisting of a usually pear-shaped piece divided into spoon-like segments that can be spread apart by turning a screw. 

pear tree

noun
  • A tree of the genus Pyrus, which bears the pears as fruits. 

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