bellarmine vs graybeard

bellarmine

noun
  • A stoneware jug of a pattern that originated around Cologne, Germany, in the 16th century, having a bearded face or mask supposed to represent Cardinal Bellarmine, a leader in the Counter-Reformation. 

graybeard

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