calamity vs cataclysm

calamity and cataclysm both are nouns.

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

As nouns, calamity and cataclysm are synonyms defined as:

Other synonyms of calamity include catastrophe, disaster, tragedy.

calamity (noun)	cataclysm (noun)
an event resulting in great loss and misfortune	an event resulting in great loss and misfortune
	a sudden violent change in the earth's surface