backstair vs roguish

backstair

adj

  • clandestine, secret or furtive 

noun

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

roguish

adj

  • Unprincipled or unscrupulous. 

  • Mischievous and playful. 

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