- An extensive overflow or sweeping flood of water; a
deluge. - Any violent catastrophe, involving sudden and extensive
changes of the earth's surface.
Meaning of 'cataclysm' (Princeton's WordNet)
1 . cataclysm
[ n]
Meaning (1): - an event resulting in great loss and misfortune
Example in sentence:
the earthquake was a disaster;
the whole city was affected by the irremediable calamity