rigor vs hardship

rigor and hardship both are nouns.

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

As nouns, rigor and hardship are synonyms defined as:

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

rigor (noun)	hardship (noun)
something hard to endure	something hard to endure
the quality of being valid and rigorous	something that causes or entails suffering
excessive sternness	a state of misfortune or affliction