backstair vs shady

backstair

adj
  • clandestine, secret or furtive 

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

shady

adj
  • Not trustworthy; disreputable. 

  • Abounding in shades. 

  • Mean, cruel. 

  • Overspread with shade; sheltered from the glare of light or sultry heat. 

  • Causing shade. 

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