a. - Appertaining to a decree; containing a decree; as, a
decretal epistle.
a. - An authoritative order or decree; especially, a letter of
the pope, determining some point or question in ecclesiastical law. The
decretals form the second part of the canon law.
a. - The collection of ecclesiastical decrees and decisions
made, by order of Gregory IX., in 1234, by St. Raymond of Pennafort.