old vs grizzly

old and grizzly both are nouns.

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

old (noun)	grizzly (noun)
past times	powerful brownish-yellow bear of the uplands of western North America

old (adjective)	grizzly (adjective)
of long duration; not new	showing characteristics of age, especially having grey or white hair
(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