Select the most appropriate meaning of the given idiom.

On edge

Nervous and unable to relax

The most appropriate meaning of the idiom "on edge" is nervous and unable to relax.

It means to be feeling anxious or tense, and to be unable to relax or feel at ease. The idiom comes from the idea of being on the edge of something, such as a cliff, which is a dangerous and unstable position.

The other options are not correct.

• Keeping things safely: This is not the same as being on edge.
• Doing exercises regularly: This is not the same as being on edge.
• Playing a tiring game: This can make you tired, but not necessarily on edge.