Gobsmacked - "Gob" is mouth in British English and if you smack it, you probably would do it because you are amazed or shocked.

Gob在英式英语里是嘴巴的意思，如果你咂嘴，可能是因为你感到惊讶或震惊。

例句：

I was gobsmacked by how much weight Pete had lost.

皮特瘦了这么多，太让我吃惊了！