[ ˌpɛnɪ'tɛnʃ(ə)ri ]
■ noun ( plural penitentiaries )
1》 N. Amer. a prison for people convicted of serious crimes.
2》 (in the Roman Catholic Church) a priest appointed to administer penance.
↘an office in the papal court deciding questions relating to penance, dispensations, etc.
Origin
ME: from med. L. paenitentiarius , from L. paenitentia 'repentance'.