killing vs matricide

killing

noun
  • An instance of someone being killed. 

  • A large amount of money. 

adj
  • That makes one ‘die’ with laughter; very funny. 

  • That literally deprives of life; lethal, deadly, fatal. 

matricide

noun
  • A person who kills his or her mother. 

  • The killing of one's mother. 

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