atrocity vs barbarism

atrocity and barbarism both are nouns.

Word	Noun	Adjective	Verb	Adverb
atrocity	Yes	No	No	No
barbarism	Yes	No	No	No

As nouns, barbarism is a hyponym of atrocity; that is, barbarism is a word with a more specific, narrower meaning than atrocity:

Other hyponyms of atrocity include barbarity, brutality, savagery, outrage, enormity.

atrocity (noun)	barbarism (noun)
an act of atrocious cruelty	a brutal barbarous savage act
the quality of being shockingly cruel and inhumane