decisive vs historic

decisive

adj
  • Marked by promptness and decision. 

  • Having the power or quality of deciding a question or controversy; putting an end to contest or controversy; final; conclusive. 

historic

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

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

  • Old-fashioned, untouched by modernity. 

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

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