concordat vs handshake

concordat

noun
  • A formal agreement between two parties, especially between a church and a state; specifically, an agreement between the Pope and a government. 

handshake

noun
  • The grasping of hands by two people when greeting, leave-taking, or making an agreement. 

  • An exchange of signals between two devices when communications begin in order to ensure synchronization. 

verb
  • To perform a handshake with another device. 

  • To perform a handshake; to shake hands. 

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