The ritual of ridding a supposedly possessed person or thing of demons. Popularly associated with the Roman Catholic Church, which has a formal exorcism ritual, with each diocese allowed to designate a priest as an exorcist. However, the church’s use of the ritual has diminished due to a greater understanding of medicine and psychology. Some Christian churches, such as Pentecostals, also perform exorcisms, although the rituals are not as elaborate and formal as the Roman Catholic ritual. Islam also has traditions that speak of exorcisms.