greybeard vs longbeard

greybeard

noun
  • An old man. 

  • A coarse earthenware vessel for holding liquor; a bellarmine. 

  • Any of the members of a group who have been there the longest, often implying experience. 

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”) 

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