confessional (n.)

"small stall in a Catholic church in which a priest sits to hear confession," 1727, from French confessional, from Medieval Latin confessionale, noun use of neuter of confessionalis (adj.), from past-participle stem of confiteri "to acknowledge" (see confess).

"pertaining to confession," mid-15c., from Medieval Latin confessionalis, from past-participle stem of confiteri "to acknowledge" (see confess).