decretal vs directional

decretal

adj
  • Pertaining to a decree. 

noun
  • A papal decree, particularly one derived from an ecclesiastical letter. 

directional

adj
  • Of or relating to guidance or help. 

  • Indicating direction. 

noun
  • Something that indicates direction, such as a vehicle's turn signal. 

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