FAMILIAR, properly meaning belonging to the family or household, but in this sense the word is rare. The more usual meanings are : friendly, intimate, well-known. "Familiar" is also used as a substantive, especially of the spirit or demon which attended on a wizard or magician. The idea underlies the notion of the Christian guardian angel and of the Roman genius natalis (see DEMONOLOGY ; WITCHCRAFT) . In the Roman Church the term is applied to persons attached to the household of the pope or of bishops.