Letters sent to all the bishops of Christendom, or one particular country, and intended to guide them in their relations with their flocks See Papal Bull
(Gr "moving in a circle"; "circulating") A letter by the head of an Orthodox jurisdiction (Archbishop or Patriarch) to those under his spiritual authority The content of such a letter may vary but it must refer to specific administrative or spiritual topics concerning the faithful
An encyclical is an official letter written by the Pope and sent to all Roman Catholic bishops, usually in order to make a statement about the official teachings of the Church. a letter sent by the Pope to all Roman Catholic bishops (encyclicus, from enkyklios , from kyklos )
Sent to many persons or places; intended for many, or for a whole order of men; general; circular; as, an encyclical letter of a council, of a bishop, or the pope