What does antediluvian mean?
Antediluvian means belonging to the time before the biblical Flood, but in everyday language it has come to describe anything extremely old-fashioned, primitive, or hopelessly out of date. The word derives from Latin 'ante' (before) combined with 'diluvium' (flood), and entered English in the seventeenth century, when writers used it seriously to refer to the era before Noah's Flood — a period early geologists genuinely believed had shaped the Earth's surface. As science moved on, the literal meaning faded, and the figurative one took over: today calling a computer, a law, or an attitude antediluvian is a wry way of saying it belongs to another age entirely. The word is mildly mocking but rarely harsh, lending a touch of literary wit to criticism. Its blend of biblical gravity and comic exaggeration makes it a favourite of essayists and reviewers, and it remains a vivid alternative to plainer terms like 'old-fashioned' or 'obsolete'.
Of or belonging to the time before the biblical Flood; extremely old-fashioned or primitive.
"Her antediluvian opinions on women in the workplace drew audible groans from the audience."
Almost always used figuratively in modern English to mock something as absurdly outdated.
A person who is very old or who holds extremely old-fashioned views.
"The committee was dominated by a few antediluvians who refused to consider any reform."
Used humorously; the plural form 'antediluvians' appears chiefly in this figurative sense.
Applies when the word is used as a noun for people of extremely old age or old-fashioned views; as an adjective, the word does not take a plural form.
"The board meeting was a standoff between the young reformers and the antediluvians."
The word literally means 'before the Flood' — so when someone calls your phone antediluvian, they're technically comparing it to life before Noah's ark.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of antediluvian
Antediluvian comes from the Latin 'ante' (before) joined to 'diluvium', the Latin word for a great flood or deluge, giving the sense 'before the Flood'. The term entered English in the seventeenth century, when biblical chronology was taken literally and the period before Noah's Flood was a real division of history. Cognate terms from the same Latin root include 'deluge', 'alluvium', and 'diluvium' itself.
How antediluvian is actually used
In modern usage the word is almost always figurative and mildly humorous or mocking, applied to ideas, technology, or attitudes that seem absurdly outdated. The literal geological/biblical sense survives mainly in older scientific and theological writing. It carries a formal-literary register but is widely understood.
Easily confused with antediluvian
'Pre-diluvian' is not a standard English word; 'antediluvian' is the correct single-word form meaning before the Flood.