cataclysm

From French cataclysme, from Latin cataclysmus, from Ancient Greek κατακλυσμός (kataklusmós, “deluge, flood”), from κατακλύζω (kataklúzō, “to dash over, flood, deluge, inundate”), from κατά (katá, “downwards, towards”) + κλύζω (klúzō, “to wash off, to wash away, to dash over”).