centenarian vs grandsire

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. 

grandsire

noun
  • Any male ancestor. 

  • The sire of a sire, paternal grandfather 

  • Any of a number of methods of change-ringing on bells. 

  • Grandfather. 

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