Definition of Escape
The departure or deliverance out of custody of a person who was lawfully imprisoned before he is entitled to his liberty by the process of law. The voluntarily or negligently allowing any person lawfully in confinement to leave. To flee from; to avoid; to get away, as to flee to avoid arrest. The voluntary departure from lawful custody by a prisoner with the intent to evade the due course of justice. People v. Rivera, Colo.App., 542 P.2d 90, 92. See 18 U.S.C.A. § 751 et seq.
That's the definition of Escape in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.