electrocute vs rub out

electrocute

verb
  • To kill by electric shock. 

  • To execute by electric shock, often by means of an electric chair. 

  • To inflict a severe electric shock (not necessarily fatal) upon. 

rub out

verb
  • To kill, especially to murder. 

  • To delete or erase or remove (something) by rubbing. 

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