catastrophe vs hard knocks

catastrophe and hard knocks both are nouns.

Word	Noun	Adjective	Verb	Adverb
catastrophe	Yes	No	No	No
hard knocks	Yes	No	No	No

As nouns, hard knocks is a hypernym of catastrophe; that is, hard knocks is a word with a broader meaning than catastrophe:

Other hypernyms of catastrophe include adversity, hardship.

catastrophe (noun)	hard knocks (noun)
an event resulting in great loss and misfortune	a state of misfortune or affliction
a sudden violent change in the earth's surface
a state of extreme (usually irremediable) ruin and misfortune