internecine vs killing

internecine

adj
  • Mutually destructive; most often applied to warfare. 

  • Characterized by struggle within a group, usually applied to an ethnic or familial relationship. 

killing

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

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

noun
  • A large amount of money. 

  • An instance of someone being killed. 

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