hoary vs nonagenarian

hoary

adj
  • White, whitish, or greyish-white. 

  • Old or old-fashioned; trite. 

  • Covered with short, dense, greyish white hairs. 

  • Of a pale silvery grey. 

  • White or grey with age. 

nonagenarian

adj
  • Of or related to ninetysomethings. 

noun
  • Synonym of ninetysomething: a person between 90 and 99 years old. 

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