deadly vs internecine

deadly

adj
  • Aiming or willing to destroy; implacable; desperately hostile. 

  • Very boring. 

  • Very accurate (of aiming with a bow, firearm, etc.). 

  • Excellent, awesome, cool. 

  • Causing death; lethal. 

adv
  • In a way which suggests death. 

  • Extremely, incredibly. 

internecine

adj
  • Mutually destructive; most often applied to warfare. 

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

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