Penitential

(pĕn'/ĭ-tĕn'/shal), a. [Fr. pénitentiel, Pr., Sp., & Pg. penitencial, It. penitenziale.] Pertaining to, proceeding from, or expressing penitence or contrition of heart. “Guilt that all the penitential fires of hereafter can not cleanse.” W. Scott.

n. (Rom. Cath. Church.) A book containing the rules which relate to penance and the reconciliation of penitents.