famine vs calamity

famine and calamity both are nouns.

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

As nouns, calamity is a hypernym of famine; that is, calamity is a word with a broader meaning than famine:

famine: a severe shortage of food (as through crop failure) resulting in violent hunger and starvation and death
calamity: an event resulting in great loss and misfortune

Other hypernyms of famine include cataclysm, catastrophe, disaster, tragedy.

famine (noun)	calamity (noun)
a severe shortage of food (as through crop failure) resulting in violent hunger and starvation and death	an event resulting in great loss and misfortune
an acute insufficiency