If you are dumbfounded, you are extremely surprised by something.
例句
I stood there dumbfounded.我站在那兒目瞪口呆。
英漢詞典釋義
adj.
驚呆的;目瞪口呆的
She was dumbfounded by the terrible news.她被這可怕的消息驚呆了。
英英詞典釋義
Adjective
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"