erase vs expunge

erase

verb
  • To be erased (have markings removed, have information removed, or be cleared of information). 

  • To remove a runner from the bases via a double play or pick off play 

  • To kill; assassinate. 

  • To obliterate (information) from a storage medium, such as to clear or to overwrite. 

  • To obliterate information from (a storage medium), such as to clear or (with magnetic storage) to demagnetize. 

  • To disregard (a group, an orientation, etc.); to prevent from having an active role in society. 

  • to remove markings or information 

noun
  • The operation of deleting data. 

expunge

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

  • To eliminate completely; to annihilate. 

  • To erase or strike out. 

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