hoar vs senectitude

hoar

noun

  • Hoariness; antiquity. 

  • A white or greyish-white colour. 

adj

  • Hoarily bearded. 

  • Of a white or greyish-white colour. 

senectitude

noun

  • old age 

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