eighties vs years

eighties and years both are nouns.

Word	Noun	Adjective	Verb	Adverb
eighties	Yes	No	No	No
years	Yes	No	No	No

eighties (noun)	years (noun)
the time of life between 80 and 90	a late time of life
the decade from 1980 to 1989	a prolonged period of time
the decade from 1880 to 1889	the time during which someone's life continues