know vs penetrate

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’ 

penetrate

verb
  • To achieve understanding of, despite some obstacle; to comprehend; to understand. 

  • To enter into; to make way into the interior of; to pierce. 

  • To move a piece past the defending pieces of one's opponent. 

  • To affect profoundly through the senses or feelings; to move deeply. 

  • To insert the penis into an opening, such as a vagina, mouth or anus. 

  • To infiltrate an enemy to gather intelligence. 

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