Decretum may refer to:The Decretum Gratiani is a collection of Canon law compiled in the twelfth century by a jurist named Gratian.Decretum Gelasianum, traditionally attributed to Pope Gelasius I, contains a list of works adjudged apocryphal.Decretum de Judaeis is the name given to the series of draft documents of the Second Vatican Council which led to ground-breaking progress in the Church's relations with Jews.… (More on Decretum)