v. t. [ imp. & p. p. Dumfounded; p. pr. & vb. n. Dumfounding. ] To strike dumb; to confuse with astonishment. [ Written also dumbfound. ] Spectator. [ 1913 Webster ]
adj. same as dumbfounded. Syn. -- amazed, astonied, astonished, astounded, flabbergasted, stunned, stupefied, thunderstruck. [ WordNet 1.5 ]
v. t. To dumfound; to confound. [ Written also dumbfounder. ] [ 1913 Webster ]
adj. same as dumbfounding. Syn. -- astonishing, astounding, dumbfounding. [ WordNet 1.5 ]