goodbye vs introductory

goodbye

noun
  • An utterance of goodbye, the wishing of farewell to someone. 

verb
  • To say goodbye; to wish somebody farewell on parting. 

intj
  • Farewell; a formula used to another person or persons when the speaker, writer, or person addressed is departing. 

introductory

adj
  • Introducing; giving a preview or idea of. 

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