centenarian vs retro

centenarian

adj
  • Of or relating to centenarians or a centenary celebration. 

  • Aged 100 years or more; extremely old. 

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

retro

adj
  • Of, or relating to, the past, past times, or the way things were. 

  • Affecting things past; retroactive, ex post facto. 

noun
  • Past fashions or trends. 

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