1.a place for imprisonment, reformatory discipline, or punishment, especially a prison maintained in the U.S. by a state or the federal government for serious offenders.
2.Roman Catholic Church. a tribunal in the Curia Romana, presided over by a cardinal (grand penitentiary), having jurisdiction over certain matters, as penance, confession, dispensation, absolution, and impediments, and dealing with questions of conscience reserved for the Holy See.