public speaking vs rhetoric

public speaking

noun
  • oratory (art of public speaking) 

  • act of speaking to a group of people in a structured manner 

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 public speaking and rhetoric occurred in a corpus of books? (source: Google Ngram Viewer )