cognizance vs concealment

cognizance

noun
  • An emblem, badge or device, used as a distinguishing mark by the body of retainers of a royal or noble house. 

  • Notice or awareness. 

  • Jurisdiction. 

concealment

noun
  • The practice of keeping secrets. 

  • protection from observation or surveillance. 

  • The condition of being hidden or concealed. 

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