be bored witless

To be extremely bored. I could tell everyone in the audience was bored witless by the end of the lecture. We thought a week in a secluded cabin with no TV or Internet would make for some great family bonding, but we were all bored out of our skulls after a couple of days. My flight's been delayed, and I'm bored witless after sitting around the airport all day.

be scared witless

To be very severely frightened or worried. I was scared witless when I heard footsteps on the staircase in the middle of the night. I'm scared witless that the tests are going to come back positive for leukemia. Janet was scared witless when she encountered that mountain lion on the trails.

scare (one) witless

To shock or frighten one very severely. (Hyperbolically alludes to scaring one so badly that they lose their sanity.) Don't sneak up on me like that, you scared me out of my wits! That car accident seems to have scared Janet out of her wits—she's still shaken by it.

scare someone witless

INFORMAL

If something or someone scares you witless, they make you very frightened or worried. I saw that film when I was in Paris and it scared me witless. You read about all these things that can cause cancer and it scares you witless.

be scared/bored ˈwitless

(informal) be extremely frightened or bored: Despite his reputation as a tough guy, he admits that he was ‘scared witless’ when he first arrived in New York.