disingenuous vs plain-speaking

disingenuous

adj
  • Assuming a pose of naïveté to make a point or for deception. 

  • Not honourable; unworthy of honour 

  • Not ingenuous; not frank or open 

plain-speaking

adj
  • Synonym of plain-spoken 

How often have the words disingenuous and plain-speaking occurred in a corpus of books? (source: Google Ngram Viewer )