1. as if struck dumb with astonishment and surprise;
"a circle of policement stood dumbfounded by her denial of having seen the accident""the flabbergasted aldermen were speechless""was thunderstruck by the news of his promotion"
2. in a state of mental numbness especially as resulting from shock;
"he had a dazed expression on his face""lay semiconscious, stunned (or stupefied) by the blow""was stupid from fatigue"