young vs age

young and age both are nouns.

Word	Noun	Adjective	Verb	Adverb
young	Yes	Yes	No	No
age	Yes	No	Yes	No

young (noun)	age (noun)
any immature animal	how long something has existed
young people collectively	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

young (adjective)	age (adjective)
(used of living things especially persons) in an early period of life or development or growth
(of crops) harvested at an early stage of development; before complete maturity
not tried or tested by experience
being in its early stage
suggestive of youth; vigorous and fresh