know vs witness

know

verb
  • To understand or have a grasp of through experience or study. 

  • To perceive the truth or factuality of; to be certain of or that. 

  • To experience. 

  • To be or become aware or cognizant. 

  • To be able to play or perform (a song or other piece of music). 

  • To be acquainted or familiar with; to have encountered. 

  • To be aware of; to be cognizant of. 

  • To recognize as the same (as someone or something previously encountered) after an absence or change. 

  • To have knowledge; to have information, be informed. 

noun
  • Knowledge; the state of knowing. 

  • Knowledge; the state of knowing; now confined to the fixed phrase ‘in the know’ 

witness

verb
  • To see or gain knowledge of through experience. 

  • To take as evidence. 

  • To furnish proof of, to show. 

  • To present personal religious testimony; to preach at (someone) or on behalf of. 

  • To see the execution of (a legal instrument), and subscribe it for the purpose of establishing its authenticity. 

noun
  • Attestation of a fact or event; testimony. 

  • One who sees or has personal knowledge of something. 

  • Someone called to give evidence in a court. 

  • One who is called upon to witness an event or action, such as a wedding or the signing of a document. 

  • Something that serves as evidence; a sign or token. 

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