carcinogenic vs internecine

carcinogenic

adj
  • Causing or tending to cause cancer. 

noun
  • Synonym of carcinogen 

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 carcinogenic and internecine occurred in a corpus of books? (source: Google Ngram Viewer )