1. greybeard(n = noun.person) graybeard, methuselah, old man - a man who is very old;
is a kind of adult male, man, golden ager, old person, oldster, senior citizen
has particulars: codger, old codger, antique, gaffer, old-timer, old geezer, oldtimer, patriarch
2. greybeard(n = noun.artifact) bellarmine, long-beard, longbeard - a stoneware drinking jug with a long neck; decorated with a caricature of Cardinal Bellarmine (17th century);
is a kind of jug
a man who is old. [WordNet 1.5]
greybeard, n. archaic 1 an old man.
2 a large stoneware jug for spirits.
3 Brit. clematis in seed.