Penitential /(?)/

Pen·i·ten·tial

Penitential

a.
  1. Of or pertaining to penitence, or to penance; expressing penitence; of the nature of penance; as, the penitential book; penitential tears.
    Guilt that all the penitential fires of hereafter can not cleanse.

Penitential

n.
  1. A book formerly used by priests hearing confessions, containing rules for the imposition of penances; -- called also penitential book. (R. C. Ch.)