curmudgeon vs golden ager

curmudgeon and golden ager both are nouns.

Word	Noun	Adjective	Verb	Adverb
curmudgeon	Yes	No	No	No
golden ager	Yes	No	No	No

As nouns, golden ager is a hypernym of curmudgeon; that is, golden ager is a word with a broader meaning than curmudgeon:

curmudgeon: a crusty irascible cantankerous old person full of stubborn ideas
golden ager: an elderly person

Other hypernyms of curmudgeon include old person, oldster, senior citizen.

curmudgeon (noun)	golden ager (noun)
a crusty irascible cantankerous old person full of stubborn ideas	an elderly person