young vs aged

young and aged both are nouns.

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

young (noun)	aged (noun)
any immature animal	people who are old collectively
young people collectively

young (adjective)	aged (adjective)
(used of living things especially persons) in an early period of life or development or growth	(used of tobacco) aging as a preservative process
(of crops) harvested at an early stage of development; before complete maturity	of wines, fruit, cheeses; having reached a desired or final condition; (`aged' pronounced as one syllable)
not tried or tested by experience	at an advanced stage of erosion (pronounced as one syllable)
being in its early stage	advanced in years; (`aged' is pronounced as two syllables)
suggestive of youth; vigorous and fresh	having attained a specific age; (`aged' is pronounced as one syllable)