discourse vs keynote

discourse

noun
  • A formal lengthy exposition of some subject, either spoken or written. 

  • Expression in words, either speech or writing. 

  • An institutionalized way of thinking, a social boundary defining what can be said about a specific topic (after Michel Foucault). 

  • Any rational expression, reason. 

verb
  • To exercise reason; to employ the mind in judging and inferring; to reason. 

  • To engage in discussion or conversation; to converse. 

  • To write or speak formally and at length. 

keynote

noun
  • The main theme of a speech, a written work, or a conference. 

  • The note on which a musical key is based; the tonic. 

  • A speech that sets the main theme of a conference or other gathering; a keynote speech or keynote address. 

verb
  • To deliver a speech that sets the main theme of a conference or other gathering. 

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