1) Agape 2) Agog 3) Astonished 4) Awed 5) Dumbstruck 6) Dumfounded 7) Flabbergasted 8) Speechless 9) Staggered 10) Stupefied 11) Surprised 12) Thunderstruck 1) Dumfounded 2) Exclusively Anglo word 3) Exclusively Saxon word 4) Flabbergasted 5) Stupefied 6) Surprised 7) Thunderstruck 8) Word of purely Anglo origin 9) Word with Anglo-Saxon origins 
[adj] - as if struck dumb with astonishment and surprise
dumfounded adjective 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`...