matchmaker vs mediator

matchmaker

noun
  • Someone who finds suitable dates or marriage partners for other people. 

  • Someone who arranges professional boxing matches. 

  • Someone who makes matchsticks. 

mediator

noun
  • One who negotiates between parties seeking mutual agreement. 

  • A chemical substance transmitting information to a targeted cell. 

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