marvelously vs terrifically

marvelously and terrifically both are adverbs.

Word	Noun	Adjective	Verb	Adverb
marvelously	No	No	No	Yes
terrifically	No	No	No	Yes

As adverbs, marvelously and terrifically are synonyms defined as:

Other synonyms of marvelously include marvellously, superbly, toppingly, wonderfully, wondrous, wondrously.

marvelously (adverb)	terrifically (adverb)
(used as an intensifier) excellently	(used as an intensifier) excellently