backstair vs mendacious

backstair

adj

  • clandestine, secret or furtive 

noun

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

mendacious

adj

  • Lying, untruthful or dishonest. 

  • False or untrue. 

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