incredulous vs questioning

incredulous

adj
  • Expressing or indicative of incredulity. 

  • Difficult to believe; incredible. 

  • Skeptical, disbelieving, or unable to believe. 

questioning

adj
  • Characterized by questions, inquisitiveness, doubt, or wonder. 

  • Unsure of one's sexual orientation and/or gender identity. 

noun
  • Interrogation. 

  • The action of asking questions; a survey; an inquiry. 

  • The act of challenging, wondering, and doubting. 

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