marvellously vs marvelously

marvellously and marvelously both are adverbs.

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

As adverbs, marvellously and marvelously are synonyms defined as:

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

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