This is a list of names in which the description contains the keyword traitor.
MatthiasmGerman, French, Dutch, Biblical, Biblical Latin, Biblical Greek From Greek Ματθίας (Matthias), a variant of Ματθαῖος (see Matthew). This form appears in the New Testament as the name of the apostle chosen to replace the traitor Judas Iscariot. This was also the name of kings of Hungary (spelled Mátyás in Hungarian), including Matthias I who made important reforms to the kingdom in the 15th century.
MordredmWelsh Mythology, Arthurian Cycle From Welsh Medraut, possibly from Latin moderatus meaning "controlled, moderated". In Arthurian legend Mordred was the illegitimate son (in some versions nephew) of King Arthur. Mordred first appears briefly (as Medraut) in the 10th-century Annales Cambriae, but he was not portrayed as a traitor until the chronicles of the 12th-century Geoffrey of Monmouth. While Arthur is away he seduces his wife Guinevere and declares himself king. This prompts the battle of Camlann, which leads to the deaths of both Mordred and Arthur.