backstair vs cottage

backstair

noun
  • The backstairs (stairs at the rear of a building). 

adj
  • clandestine, secret or furtive 

cottage

noun
  • A small house. 

  • A seasonal home of any size or stature, a recreational home or a home in a remote location. 

  • A meeting place for homosexual men. 

verb
  • To have homosexual sex in a public lavatory; to practice cottaging. 

  • To stay at a seasonal home, to go cottaging. 

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