diction vs rhetoric

diction

noun
  • Choice and use of words, especially with regard to effective communication. 

  • Enunciation, pronunciation. 

  • The effectiveness and degree of clarity of word choice and expression. 

rhetoric

noun
  • The art of using language, especially public speaking, as a means to persuade. 

  • Meaningless language with an exaggerated style intended to impress. 

adj
  • Synonym of rhetorical. 

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