centenarian vs geriatric

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. 

geriatric

adj
  • Elderly, old. 

  • Relating to geriatrics. 

  • Relating to the elderly. 

noun
  • An old person. 

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