1) the money or bond put up to secure the release of a person who has been charged with a crime. for minor crimes bail is usually set by a schedule which will show the amount to be paid before any court appearance (arraignment). for more serious crimes the amount of bail is set by the judge at the suspect’s first court appearance. the theory is that bail guarantees the appearance of the defendant in court when required. while the constitution guarantees the right to reasonable bail, a court may deny bail in cases charging murder or treason, or when there is a danger that the defendant will flee or commit mayhem. in some traffic matters the defendant may forfeit the bail by non-appearance since the bail is equivalent to the fine. 2) to post money or bond to secure an accused defendant’s release. this is generally called “bailing out” a prisoner.