marvellously vs wondrous

marvellously is not an adjective while wondrous is an adjective.

Word	Noun	Adjective	Verb	Adverb
marvellously	No	No	No	Yes
wondrous	No	Yes	No	Yes

As adverbs, marvellously and wondrous are synonyms defined as:

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

marvellously (adjective)	wondrous (adjective)
	extraordinarily good or great; used especially as intensifiers

marvellously (adverb)	wondrous (adverb)
(used as an intensifier) excellently	(used as an intensifier) excellently