Synonyms for Greybeard (same or very similar meaning)
WordNet sense 1 (a man who is very old):
graybeard, methuselah, old manWordNet sense 2 (a stoneware drinking jug with a long neck; decorated with a caricature of Cardinal Bellarmine (17th century)):
bellarmine, longbeard, long-beardFrom the ODE community, based on WordNetadd/edit