old-timer vs Methuselah

old-timer and Methuselah both are nouns.

Word	Noun	Adjective	Verb	Adverb
old-timer	Yes	No	No	No
Methuselah	Yes	No	No	No

As nouns, Methuselah is a hypernym of old-timer; that is, Methuselah is a word with a broader meaning than old-timer:

Other hypernyms of old-timer include graybeard, greybeard, old man.

old-timer (noun)	Methuselah (noun)
an elderly man	(Old Testament) a patriarch (grandfather of Noah) who is said to have lived 969 years
an experienced person who has been through many battles; someone who has given long service	a man who is very old