dumbstruck vs dumfounded

dumbstruck and dumfounded both are adjectives.

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

As adjectives, dumbstruck and dumfounded are synonyms defined as:

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

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

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