Select the most appropriate meaning of the given idiom.

To smell a rat

To suspect something

The most appropriate meaning of the idiom "to smell a rat" is to suspect something.

It is used to describe someone who has a feeling that something is wrong or suspicious. The idiom is thought to have originated from the idea that rats are associated with filth and disease, and so someone who smells a rat is likely to be suspicious of something that is not clean or healthy.

For example, you might say "I'm starting to smell a rat in this deal." This means that you are suspicious of the deal and that you think something is wrong with it.

The other options are not accurate descriptions of the meaning of the idiom.

• To catch someone during a crime: This idiom is more accurately described as "to apprehend someone in the act of committing a crime."
• To leave things undisturbed: This idiom is more accurately described as "to keep things as they are."
• To detect a dead rat: This is the literal meaning of the idiom, but it is not the idiomatic meaning.