cataclysm vs disaster

cataclysm and disaster both are nouns.

Word	Noun	Adjective	Verb	Adverb
cataclysm	Yes	No	No	No
disaster	Yes	No	No	No

As nouns, cataclysm and disaster are synonyms defined as:

Other synonyms of cataclysm include calamity, catastrophe, tragedy.

cataclysm (noun)	disaster (noun)
an event resulting in great loss and misfortune	an act that has disastrous consequences
a sudden violent change in the earth's surface	an event resulting in great loss and misfortune
	a state of extreme (usually irremediable) ruin and misfortune