megadeath vs slaughter

megadeath

noun
  • One million deaths, especially as a unit of measure in reference to nuclear warfare. 

slaughter

noun
  • A massacre; the killing of a large number of people. 

  • A rout or decisive defeat. 

  • A mass destruction of non-living things. 

  • The killing of animals, generally for food. 

  • A group of iguanas. 

verb
  • To butcher animals, generally for food. 

  • To kill someone or something, especially in a particularly brutal manner. 

  • To massacre people in large numbers. 

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