(Latin: festum duplex)
A rank given to the more important festivals of the year. The most solemn are called doubles of the first class, e.g., Christmas and the Epiphany; next come doubles of the second class, the feasts of some of the Apostles; then major doubles (duplicia majora); and ordinary doubles. The term "double" is used for all of these because in the Sacred Office the antiphon of each psalm is given in full before the psalm as well as after, i.e.,it is doubled for each psalm, except for the Little Hours when it is repeated after the three psalms for each.