genarian vs older adult

genarian

noun
  • An elderly person, especially one over the age of 60. 

adj
  • Concerning rules or principles as opposed to acts. 

older adult

noun
  • An old person. 

  • Used other than figuratively or idiomatically: see older, adult. 

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