pen·i·ten·tia·ry 
(pĕn′ĭ-tĕnshə-rē)
(pĕn′ĭ-tĕnshə-rē)n. pl. pen·i·ten·tia·ries
1. A prison for those convicted of major crimes.
2. Roman Catholic Church
a. A tribunal of the Roman Curia having jurisdiction in matters relating to penance, dispensations, and papal absolutions.
b. A priest whose special function is the administration of the sacrament of penance in a particular church or diocese.
adj.
1. Of or for the purpose of penance; penitential.
2. Relating to or used for punishment or reform of criminals or wrongdoers.
3. Resulting in or punishable by imprisonment in a penitentiary: a penitentiary offense.
[Middle English penitenciarie, penance officer, episcopal prison, from Medieval Latin pēnitentiāria, feminine of pēnitentiārius, from Latin paenitentia, penitence, from paenitēns, penitent; see PENITENT.]