grievous vs atrocious

grievous and atrocious both are adjectives.

Word	Noun	Adjective	Verb	Adverb
grievous	No	Yes	No	No
atrocious	No	Yes	No	No

As adjectives, grievous and atrocious are synonyms defined as:

Other synonyms of grievous include flagitious, monstrous.

grievous (adjective)	atrocious (adjective)
causing fear or anxiety by threatening great harm	provoking horror
shockingly brutal or cruel	exceptionally bad or displeasing
of great gravity or crucial import; requiring serious thought	shockingly brutal or cruel
causing or marked by grief or anguish