gaga vs old

gaga is not a noun while old is a noun.

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

gaga (noun)	old (noun)
	past times

gaga (adjective)	old (adjective)
intensely enthusiastic about or preoccupied with	of long duration; not new
mentally or physically infirm with age	(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