darkened vs old

darkened is not a noun while old is a noun.

Word	Noun	Adjective	Verb	Adverb
darkened	No	Yes	No	No
old	Yes	Yes	No	No

darkened (noun)	old (noun)
	past times

darkened (adjective)	old (adjective)
become or made dark by lack of light	of long duration; not new
(of fabrics and paper) grown dark in color over time	(used especially of persons) having lived for a relatively long time or attained a specific age
	skilled through long experience
	(used for emphasis) very familiar
	excellent
	just preceding something else in time or order
	belonging to some prior time