internecine vs suicidal

internecine

adj
  • Mutually destructive; most often applied to warfare. 

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

suicidal

adj
  • Highly likely to certain to result in the deaths of the participants; dangerous or reckless to such a degree as to be tantamount to suicide for those taking part. 

  • Likely to commit, or to attempt to commit, suicide. 

  • Extremely reckless. 

  • Pertaining to suicide. 

noun
  • Someone suicidal; someone likely to kill themselves. 

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