longbeard vs old boy

longbeard

noun
  • Synonym of greybeard (“an old man”) 

  • A man with a long beard. 

  • Synonym of greybeard (“experienced long-time member of a group”) 

  • Synonym of greybeard (“a bellarmine”) 

old boy

noun
  • An old man. 

  • An alumnus, especially of a public school. 

  • A former member of a group. 

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