Bail

». To procure the release of a person from legal custody, by undertaking that he shall appear at the time and place designated and submit himself to the jurisdiction and judgment of the court. To set at liberty a-person arrested or imprisoned, on security being taken for his appearance on a day and a place certain, which securily is called “bail,” because the party arrested or imprisoned is delivered into the hands of those who bind themselves for his appearance when required,) in order that ha may be safely protected from prison.

Wharton.