dumfounding vs unbelievable

dumfounding and unbelievable both are adjectives.

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

dumfounding (adjective)	unbelievable (adjective)
bewildering or striking dumb with wonder	beyond belief or understanding
	having a probability too low to inspire belief