centenarian vs former

centenarian

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

adj
  • Aged 100 years or more; extremely old. 

  • Of or relating to centenarians or a centenary celebration. 

former

noun
  • Someone who forms something; a maker; a creator or founder. 

  • An object used to form something, such as a template, gauge, or cutting die. 

  • Someone in, or of, a certain form (class). 

adj
  • First of aforementioned two items. Used with the, often without a noun. 

  • Previous. 

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