DUMBFOUNDED

adj. dumfounded, amazed, shocked, surprised, startled, astonished, astounded, bewildered, staggered, floored, nonplussed, overwhelmed, speechless, stunned, thunderstruck, dazzled, dazed, dumbstruck, taken aback, confused, confounded, bemused, perplexed, baffled, disconcerted, Colloq bowled over, flabbergasted, knocked out, thrown (off), US thrown for a loss, Brit knocked for six, knocked sideways She is dumbfounded that he proposed marriage