WordNet sense 1 (any of the early patriarchs who lived prior to the Noachian deluge):

antediluvian patriarch

WordNet sense 2 (a very old person):

ancient

WordNet sense 3 (of or relating to the period before the biblical flood):

antediluvial

WordNet sense 4 (so extremely old as seeming to belong to an earlier period):

antiquated, archaic

WordNet sense 5 (of long duration; not new):

old