1.  methuselah(n = noun.person) - (Old Testament) a patriarch (grandfather of Noah) who is said to have lived 969 years;
is a kind of patriarch

2.  methuselah(n = noun.person) graybeard, greybeard, 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

methuselah, n.
1 a very old person or thing.
2 (methuselah) a wine bottle of about eight times the standard size.

Etymology:
ME: the name of a patriarch said to have lived 969 years (Gen. 5:27)

N  veteran, old man, seer, patriarch, graybeard, grandfather, grandsire, grandam, gaffer, gammer, crone, pantaloon, sexagenarian, octogenarian, nonagenarian, centenarian, old stager, dotard, preadamite, Methuselah, Nestor, old Parr, elders, forefathers, superfluous lags the veteran on the stage.