irony vs rhetorical question

irony

noun
  • Contradiction between circumstances and expectations; condition contrary to what might be expected. 

  • Dramatic irony: a theatrical effect in which the meaning of a situation, or some incongruity in the plot, is understood by the audience, but not by the characters in the play. 

  • Socratic irony: ignorance feigned for the purpose of confounding or provoking an antagonist. 

  • The quality of a statement that, when taken in context, may actually mean something different from, or the opposite of, what is written literally; the use of words expressing something other than their literal intention, often in a humorous context. 

  • An ironic statement. 

adj
  • Of or pertaining to the metal iron. 

  • The food had an irony taste to it. 

rhetorical question

noun
  • A question to which the asker does not expect an answer. 

  • A question posed only for dramatic or persuasive effect. 

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