antediluvian vs antiquated

antediluvian is a noun but antiquated is not a noun.

Word	Noun	Adjective	Verb	Adverb
antediluvian	Yes	Yes	No	No
antiquated	No	Yes	No	No

As adjectives, antediluvian and antiquated are synonyms defined as:

antediluvian and antiquated: so extremely old as seeming to belong to an earlier period

Other synonyms of antediluvian include archaic.

antediluvian (noun)	antiquated (noun)
a very old person
any of the early patriarchs who lived prior to the Noachian deluge

antediluvian (adjective)	antiquated (adjective)
of or relating to the period before the biblical flood	so extremely old as seeming to belong to an earlier period
so extremely old as seeming to belong to an earlier period