Bull, in the Roman Catholic Church, is a decree or mandate issued by the pope on important or solemn occasions. The term comes from the Latin word bulla, which means seal. For centuries, lead seals were placed on papal bulls. Since 1878, most bulls have been stamped with a wax seal. Copies of a bull are sent to Catholic churches throughout the world, while the original is kept in Rome. A bull differs from an encyclical, which is a letter the pope addresses to the church and people of good will on important questions.
