antediluvian
- Ridiculously old-fashioned or outdated; belonging to a time long past.
- Literally, of or relating to the period before the biblical Flood described in Genesis.
In a sentence
- The antediluvian filing system—paper cards organized by color—baffled every new hire at the archive.
- Fossil hunters unearthed antediluvian bones in the riverbed, offering clues to species that vanished millions of years ago.
Usage note. The word's meaning shifts subtly between literal (pre-Flood) and figurative (absurdly old-fashioned); context usually clarifies which is intended. Pronunciation catches people out: the stress falls on the third syllable '-lu-', not the first.
Where it comes from
English antediluvian — “before the biblical flood” · entered English mid-17th c.
Formed in English in the mid-17th century from Latin 'ante' (before) and 'diluvium' (flood, deluge), derived from 'diluere' (to wash away), from 'di-' (apart) and 'luere' (to wash). Theologians and natural philosophers coined it to describe creatures or events predating Noah's Flood. The figurative sense of 'hopelessly old-fashioned' developed later, playing on the extreme age implied (source: Merriam-Webster, Oxford).