Collecta, in liturgical phraseology, is
(1) the collecting of alms or contributions of the faithful. From Leo the Great we learn that such a collection was sometimes made on a Sunday, sometimes on Monday or Tuesday, for the benefit and sustenance of the poor. These collections seem to have been distinct from oblations.
(2) The gathering together of the people for divine service. Jerome (Epist. 27) states that the sound of Alleluia called monks to say their offices (ad collectam). Pachomius (Regula, c. 17) speaks of the collecta in which oblation was made; he also distinguishes between the collecta domus, the service held in the several houses of a monastery, and the collecta major, at which the whole body of monks was brought together to say their offices. In this rule, collecta has very probably the same sense as Collatio.
(3) A society or brotherhood. So in the 15th canon of the first council of Nantes (Hincmar, Capitula ad Presbyt. c. 14).