scare (one) silly Meaning To shock or frighten one very sudd | English Choice

scare (one) silly

Meaning
To shock or frighten one very suddenly or severely. Hyperbolically alludes to frightening one so severely as to cause them to lose their mind.

For example

Don't sneak up on me like that, you scared me silly!

That car accident seems to have scared Janet silly. She's still shaken by it.