noun

1. One who lived prior to Noah's Flood.

adjective

1. Ancient or antiquated.

2. Extremely dated.

   “Those ideas are antediluvian.”

3. Pertaining or belonging to the time period prior to a great or destructive flood or deluge.

Synonyms: antediluvial, antediluvial, old, prehistoric, dated, old-fashioned, preflood