CATACLYSM
calamity, catastrophe, disaster, tragedy, cataclysm
(noun) an event resulting in great loss and misfortune; “the whole city was affected by the irremediable calamity”; “the earthquake was a disaster”
catastrophe, cataclysm
(noun) a sudden violent change in the earth’s surface
Source: WordNet® 3.1
Etymology
Noun
cataclysm (plural cataclysms)
A sudden, violent event.
(geology) A sudden and violent change in the earth's crust.
A great flood.
Source: Wiktionary
Cat"a*clysm, n. Etym: [L. cataclysmos, Gr. cataclysme.]
1. An extensive overflow or sweeping flood of water; a deluge.
2. (Geol.)
Definition: Any violent catastrophe, involving sudden and extensive changes
of the earth's surface.
Source: Webster’s Unabridged Dictionary 1913 Edition