extremity vs hardship

extremity and hardship both are nouns.

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

As nouns, hardship is a hypernym of extremity; that is, hardship is a word with a broader meaning than extremity:

extremity: an extreme condition or state (especially of adversity or disease)
hardship: a state of misfortune or affliction

Other hypernyms of extremity include adversity, hard knocks.

extremity (noun)	hardship (noun)
an external body part that projects from the body	something hard to endure
that part of a limb that is farthest from the torso	something that causes or entails suffering
the outermost or farthest region or point	a state of misfortune or affliction
the greatest or utmost degree
an extreme condition or state (especially of adversity or disease)