strike dumb

Some of the other children had been talking, but they stopped as if struck dumb.

I was struck dumb at this, and it took a moment to find my voice.

I stood there at a loss for words, struck dumb.

I was now struck dumb indeed, and had not one word to say.

And for the second time in one minute, I was struck dumb.

As for those who survived, they were too often struck dumb.

It was no good asking, they were all struck dumb.

What he actually wanted to say was,I'm struck dumb with love.

The club had suddenly been, so to speak, struck dumb.

The men who entered with him were struck dumb at what they saw.