historic vs life-or-death

historic

adj
  • Very important; noteworthy: having importance or significance in history. 

  • Synonym of historical: of, concerning, or in accordance with recorded history or the past generally (See usage notes.) 

  • Old-fashioned, untouched by modernity. 

  • Various grammatical tenses and moods specially used in retelling past events. 

life-or-death

adj
  • Of critical importance to the success of a particular endeavor. 

  • Having death as a possible or even likely outcome; perilous. 

  • Of critical importance to the survival of a living organism. 

How often have the words historic and life-or-death occurred in a corpus of books? (source: Google Ngram Viewer )