strike dumb (verb)

1. The breathtaking beauty of the painting struck him dumb and left him in awe.

2. Her lover's unexpected proposal struck her dumb for a few moments before she could find her words.

3. The hilarious punchline in the cartoon left him laughing so hard that it struck him dumb for a while.

4. As the dragon appeared out of thin air, the sight struck the villagers dumb with fear and astonishment.