hardship vs severity

hardship and severity both are nouns.

Word	Noun	Adjective	Verb	Adverb
hardship	Yes	No	No	No
severity	Yes	No	No	No

As nouns, hardship and severity are synonyms defined as:

Other synonyms of hardship include asperity, grimness, rigor, rigorousness, rigour, rigourousness, severeness.

hardship (noun)	severity (noun)
something hard to endure	excessive sternness
something that causes or entails suffering	used of the degree of something undesirable e.g. pain or weather
a state of misfortune or affliction	something hard to endure
	extreme plainness