longbeard vs oldster

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”) 

oldster

noun
  • Someone who is old. 

  • A midshipman of four years' standing; a master's mate. 

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