say it: KAT-uh-klis-uhm
cataclysm is a noun meaning "a sudden violent change in the earth's surface". It carries 2 recorded senses.
a sudden violent change in the earth's surface
an event resulting in great loss and misfortune
“the whole city was affected by the irremediable calamity”
“the earthquake was a disaster”
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for cataclysm come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.