Epithet
An epithet (from Ancient Greek ἐπίθετον (epítheton) 'adjective', from ἐπίθετος (epíthetos) 'additional'), also a byname, is a descriptive term (word or phrase) commonly accompanying or occurring in place of the name of a real or fictitious person, place, or thing. It is usually literally descriptive, as in Alexander the Great, Suleiman the Magnificent and Richard the Lionheart, or allusive, as in Edward the Confessor, William the Conqueror, Æthelred the Unready, Mehmed the Conqueror, and Bloody Mary.