old vs ancient

old and ancient both are nouns.

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

old (noun)	ancient (noun)
past times	a person who lived in ancient times
	a very old person

old (adjective)	ancient (adjective)
of long duration; not new	very old
(used especially of persons) having lived for a relatively long time or attained a specific age	belonging to times long past especially of the historical period before the fall of the Western Roman Empire
skilled through long experience
(used for emphasis) very familiar
excellent
just preceding something else in time or order
belonging to some prior time