mid-seventies vs age

mid-seventies and age both are nouns.

Word	Noun	Adjective	Verb	Adverb
mid-seventies	Yes	No	No	No
age	Yes	No	Yes	No

mid-seventies (noun)	age (noun)
the time of life between 70 and 80	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