delete vs expunge

delete

verb
  • To defeat or dominate. 

  • To kill or murder. 

  • To remove, get rid of or erase, especially written or printed material, or data on a computer or other device. 

noun
  • A remainder of a music or video release. 

  • The delete character (U+007F or %7F). 

  • A deletion. 

expunge

verb
  • To erase or strike out. 

  • To eliminate completely; to annihilate. 

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

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