assist vs expunge

assist

verb
  • To help. 

  • To make a pass that leads directly towards scoring. 

  • To help compensate for what is missing with the help of a medical technique or therapy. 

noun
  • A decisive pass made to the goal scorer 

  • A helpful action or an act of giving. 

  • A defensive play, allowing a teammate to record a putout. 

expunge

verb
  • To eliminate completely; to annihilate. 

  • To delete permanently (e-mail etc.) that was previously marked for deletion but still stored. 

  • To erase or strike out. 

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