What is Breach Of Prison?

Legal Definition
An unlawful escape out of prison. This is of itself a misdemeanor. 1 Russ. Cr. 378; 4 Bl. Com. 129 2 Hawk. P. C. c. 18, s. 1 7 Conn. 752. The remedy for this offence is by indictment. See Escape.
-- Bouviers Law Dictionary
Legal Definition
The offence of actually and forcibly breaking a prison or gaol, with intent to escape. 4 Chit. Bl. 130, notes; 4 Steph. Comm. 255. The escape from custody of a person lawfully arrested on criminal process.
-- Black's Law Dictionary
Legal Definition
A breaking out of prison.
-- Ballentine's Law Dictionary