centenarian vs centennial

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. 

centennial

adj
  • Lasting or aged a hundred years. 

  • Relating to, or associated with, the commemoration of an event that happened a hundred years before. 

  • Happening once in a hundred years. 

noun
  • The hundredth anniversary of an event or happening. 

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