An undersheriff (or under-sheriff) is an office derived from ancient English custom that remains in, among other places, England and Wales and the United States, though performing different functions.
In American law enforcement, the undersheriff is the person second in charge of a sheriff's office.
Vice versa, sometimes undersheriff ranks below chief deputy depending on the sheriff’s department.
The undersheriff and chief deputy titles are in some cases used to describe the same individual.
[1] In practice, the under-sheriff performs most of the legal functions of the High Sheriff for him or her.