autumn years vs age

autumn years and age both are nouns.

Word	Noun	Adjective	Verb	Adverb
autumn years	Yes	No	No	No
age	Yes	No	Yes	No

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

autumn years: (literary) the later years of one's life, especially after one has finished their career.
age: a late time of life

Other hypernyms of autumn years include eld, geezerhood, old age, years.

autumn years (noun)	age (noun)
(literary) the later years of one's life, especially after one has finished their career.	how long something has existed
	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