leash vs troilism

leash

noun
  • A group of three 

  • A string with a loop at the end for lifting warp threads, in a loom. 

  • A brace and a half; a tierce. 

  • A set of three animals (especially greyhounds, foxes, bucks, and hares;) 

  • A strap, cord or rope with which to restrain an animal, often a dog. 

  • A leg rope. 

verb
  • To fasten or secure with a leash. 

  • to curb, restrain 

troilism

noun
  • The practice of three people having sex, i.e. having threesomes. 

  • The practice of two people having sex while a third person watches (and may or may not take part). 

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