eighties vs decade

eighties and decade both are nouns.

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

As nouns, decade is a hypernym of eighties; that is, decade is a word with a broader meaning than eighties:

Other hypernyms of eighties include decennary, decennium.

As nouns, decade is a hypernym of eighties; that is, decade is a word with a broader meaning than eighties:

Other hypernyms of eighties include decennary, decennium.

eighties (noun)	decade (noun)
the time of life between 80 and 90	the cardinal number that is the sum of nine and one; the base of the decimal system
the decade from 1980 to 1989	a period of 10 years
the decade from 1880 to 1889