dumbstruck
adj. 被吓得目瞪口呆的,吓得发懵的
If you are dumbstruck, you are so shocked or surprised that you cannot speak.
We were dumbstruck. We just couldn't believe our eyes when she appeared.
我们惊呆了。她出现时我们简直不敢相信自己的眼睛。
He was dumbstruck at the news.
听了那个消息,他惊得目瞪口呆.