antediluvian

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Bible Occurring or belonging to the era before the Flood.
• adjective Extremely old or old-fashioned. synonym: old.

from The Century Dictionary.

• Existing before the flood (the Noachian deluge) recorded in Genesis; relating to the times or events before the Noachian deluge: as, the antediluvian patriarchs: by extension, applied to the time preceding any great flood or inundation, as that which is said to have occurred in China in the time of Yao, 2298 b. c.
• Belonging to very ancient times; antiquated; primitive; rude; simple: as, antediluvian ideas.
• noun One who lived before the deluge.
• noun Hence, humorously
• noun One who is very old or very antiquated in manners or notions; an old fogy.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Of or relating to the period before the Deluge in Noah's time; hence, antiquated.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective ancient or antiquated; old; prehistoric.
• adjective Supremely dated.
• adjective Pertaining or belonging to the time period prior to a great or destructive flood or deluge
• adjective biblical Pertaining or belonging to the time prior to Noah's Flood.
• noun One who lived prior to Noah's Flood.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a very old person
• adjective so extremely old as seeming to belong to an earlier period
• noun any of the early patriarchs who lived prior to the Noachian deluge
• adjective of or relating to the period before the biblical flood