austerity vs asceticism

austerity and asceticism both are nouns.

Word	Noun	Adjective	Verb	Adverb
austerity	Yes	No	No	No
asceticism	Yes	No	No	No

As nouns, austerity and asceticism are synonyms defined as:

austerity and asceticism: the trait of great self-denial (especially refraining from worldly pleasures)

Other synonyms of austerity include nonindulgence.

austerity (noun)	asceticism (noun)
the trait of great self-denial (especially refraining from worldly pleasures)	rigorous self-denial and active self-restraint
	the trait of great self-denial (especially refraining from worldly pleasures)
	the doctrine that through renunciation of worldly pleasures it is possible to achieve a high spiritual or intellectual state