- belonging to the ages before the biblical Flood (Genesis 7, 8)
- old-fashioned or antiquated
- an antediluvian person or thing
WordReference Random House Learner's Dictionary of American English © 2026
an•te•di•lu•vi•an /ˌæntidɪˈluviən/USA pronunciation
adj.
WordReference Random House Unabridged Dictionary of American English © 2026- Bible[often: before a noun] of or belonging to the period before the Flood in the Bible.
- old-fashioned;
antiquated:Antediluvian ideas kept the company from going forward.
an•te•di•lu•vi•an
(an′tē di lo̅o̅′vē ən),USA pronunciation adj.
n.
- Bibleof or belonging to the period before the Flood. Gen. 7, 8.
- very old, old-fashioned, or out of date;
antiquated;
primitive:antediluvian ideas.
n.
- a person who lived before the Flood.
- a very old or old-fashioned person or thing.
- ante- + Latin dīluvi(um) a flood, deluge + -an 1640–50
Collins Concise English Dictionary © HarperCollins Publishers::
antediluvian /ˌæntɪdɪˈluːvɪən; -daɪ-/ adj
'antediluvian' also found in these entries (note: many are not synonyms or translations):