Antediluvian means "before the flood" — that is, the Biblical flood with Noah's ark. Generally, though, the word is used — often humorously — to describe something really, really old.

In popular language, antediluvian is almost always used to exaggerate how comically, ridiculously old and out-of-date something is. You may laugh at your parents' antediluvian ideas of what's proper for going out on a date. And how about those antediluvian computers they still insist are fine! When the word was coined in the seventeenth century, however, it was meant literally. Back then, the science of reconstructing the Earth's history used the Bible as a frame of reference.

Definitions of antediluvian
  1. adjective
    of or relating to the period before the biblical flood
    antediluvian man”
    synonyms: antediluvial
  2. adjective
    so extremely old as seeming to belong to an earlier period
    “a ramshackle antediluvian tenement”
    antediluvian ideas”
    synonyms: antiquated, archaic
    of long duration; not new
  3. noun
    any of the early patriarchs who lived prior to the Noachian deluge
    synonyms: antediluvian patriarch
    see moresee less
    type of:
    any of the early biblical characters regarded as fathers of the human race
  4. noun
    a very old person
    synonyms: ancient
Word Family

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