incisive vs not clear

incisive

adj
  • Accurate and sharply focused. 

  • Intelligently analytical and concise. 

  • Having the quality of incising, cutting, or penetrating, as with a sharp instrument. 

  • Quickly proceeding to judgment and forceful in expression. 

  • Of or relating to the incisors. 

not clear

How often have the words incisive and not clear occurred in a corpus of books? (source: Google Ngram Viewer )