age vs year dot

age and year dot both are nouns.

Word	Noun	Adjective	Verb	Adverb
age	Yes	No	Yes	No
year dot	Yes	No	No	No

As nouns, year dot is a hyponym of age; that is, year dot is a word with a more specific, narrower meaning than age:

Other hyponyms of age include month of Sundays, aeon, eon, blue moon.

age (noun)	year dot (noun)
how long something has existed	as long ago as anyone can remember
a time of life (usually defined in years) at which some particular qualification or power arises
a late time of life
an era of history having some distinctive feature
a prolonged period of time