dumbfounding vs unbelievable

dumbfounding and unbelievable both are adjectives.

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

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