infanticide vs matricide

infanticide

noun
  • The murder of an infant. 

  • The murderer of a child: a person who has committed infanticide. 

  • The criminal offence of killing of a newborn, committed by its mother while psychologically disturbed by the effects of childbirth or lactation, not regarded as murder. 

  • The killing of a young, immature animal by a mature adult of the same species. 

  • The murder of a child by a parent; filicide. 

matricide

noun
  • The killing of one's mother. 

  • A person who kills his or her mother. 

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