unbelievable vs marvellous

unbelievable and marvellous both are adjectives.

Word	Noun	Adjective	Verb	Adverb
unbelievable	No	Yes	No	No
marvellous	No	Yes	No	No

unbelievable (adjective)	marvellous (adjective)
beyond belief or understanding	extraordinarily good or great; used especially as intensifiers
having a probability too low to inspire belief	too improbable to admit of belief
	being or having the character of a miracle