back door vs hind part

back door

adj
  • Achieved through indirect means. 

  • The path of a pitch which starts outside and then slides over the plate. 

verb
  • To enter a tube by accelerating from behind; to surf into an already formed hollow wave, in contrast to the normal method of slowing to allow a surfable wave to form. 

  • To attempt to accomplish by indirect means, especially when direct means are proscribed. 

  • to add a backdoor (a secret means of access) to a program or system. 

noun
  • The anus, generally used in reference to anal sex. 

  • The rear side of the hole, furthest from the golfer. 

  • A secret means of access to a program or system. 

  • A subsidiary entrance to a building or house at its rear, normally away from the street. 

  • A means of access, often secret and unprotected, to something. 

  • A rear side door of a car, or at the back of a van. 

hind part

How often have the words back door and hind part occurred in a corpus of books? (source: Google Ngram Viewer )