centenarian vs grizzled

centenarian

adj
  • Aged 100 years or more; extremely old. 

  • Of or relating to centenarians or a centenary celebration. 

noun
  • One who or that which is at least 100 years old. 

grizzled

adj
  • greyed, old 

  • streaked or mixed with grey; grizzly; griseous 

  • grey or partly grey 

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