dumfounded vs flabbergasted

dumfounded and flabbergasted both are adjectives.

Word	Noun	Adjective	Verb	Adverb
dumfounded	No	Yes	No	No
flabbergasted	No	Yes	No	No

As adjectives, dumfounded and flabbergasted are synonyms defined as:

dumfounded and flabbergasted: as if struck dumb with astonishment and surprise

Other synonyms of dumfounded include dumbfounded, dumbstricken, dumbstruck, stupefied, thunderstruck.

dumfounded (adjective)	flabbergasted (adjective)
as if struck dumb with astonishment and surprise	as if struck dumb with astonishment and surprise