Select the most appropriate meaning of the given idiom.

Dark horse

AN unexpected winner 

The most appropriate meaning of the idiom "dark horse" is an unexpected winner.

This idiom is used to describe someone who is not expected to succeed in a competition, but who does surprisingly well. It is often used in sports, politics, and other competitive fields.

For example, a dark horse candidate in an election is someone who is not well-known or well-funded, but who has a chance of winning. A dark horse horse in a race is a horse that is not expected to win, but which has the potential to do so.

The other options are not as accurate.

• An honest fellow - This option is not accurate because the idiom does not have anything to do with honesty.
• A mean person - This option is not accurate because the idiom does not have anything to do with meanness.
• A slow runner - This option is not accurate because the idiom is not about speed.