marvellous vs unbelievable

marvellous and unbelievable both are adjectives.

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

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