Antediluvian

1. noun

   any of the early patriarchs who lived prior to the Noachian deluge

   Similar: antediluvian patriarch

2. adjective

   so extremely old as seeming to belong to an earlier period

   “a ramshackle antediluvian tenement”

   Similar: antiquated, archaic

3. adjective

   of or relating to the period before the biblical flood

   “antediluvian man”

   Similar: antediluvial

4. noun

   a very old person

   Similar: ancient