disingenuously vs observantly

disingenuously

adv
  • In a manner that is not frank or open; deceptively. 

  • In an unnoble manner; in a manner unbecoming of true honor or dignity; unworthily. 

  • In a manner that adopts a pose of naïveté, possibly to make a point or to deceive. 

observantly

adv
  • In an observant manner. 

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