year dot vs years

year dot and years both are nouns.

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

As nouns, years is a hypernym of year dot; that is, years is a word with a broader meaning than year dot:

Other hypernyms of year dot include age, long time.

year dot (noun)	years (noun)
as long ago as anyone can remember	a late time of life
	a prolonged period of time
	the time during which someone's life continues