scare/frighten someone witless
US /skɛr/ˈfraɪtən ˈsʌmˌwʌn ˈwɪtlɪs/
UK /skɛr/ˈfraɪtən ˈsʌmˌwʌn ˈwɪtlɪs/

1.
把某人嚇得魂不附體, 把某人嚇得不知所措
to frighten someone so much that they are unable to think clearly or act sensibly
:
•
The sudden loud noise scared him witless.
突如其來的巨響把他嚇得魂不附體。
•
The ghost story frightened the children witless.
那個鬼故事把孩子們嚇得魂不附體。