atrociously vs terribly

atrociously and terribly both are adverbs.

Word	Noun	Adjective	Verb	Adverb
atrociously	No	No	No	Yes
terribly	No	No	No	Yes

As adverbs, atrociously and terribly are synonyms defined as:

Other synonyms of atrociously include abominably, abysmally, awfully, rottenly.

atrociously (adverb)	terribly (adverb)
in a terrible manner	used as intensifiers
to an extravagant or immoderate degree	in a terrible manner