illicit meeting vs tryst

illicit meeting

tryst

verb
  • To keep a tryst, to meet at an agreed place and time. 

  • To make a tryst; to agree to meet at a place. 

  • To arrange or appoint (a meeting time etc.). 

noun
  • A prearranged meeting or assignation, now especially between lovers to meet at a specific place and time. 

  • A market fair, especially a recurring one held on a schedule, where livestock sales took place. 

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