From Θαδδαιος (Thaddaios), the Greek form of the Aramaic name Thaddai. It is possibly derived from a word meaning "heart", but it may in fact be an Aramaic form of a Greek name such as Θεοδωρος (see Theodore). In the Gospel of Matthew, Thaddaeus is listed as one of the twelve apostles, though elsewhere in the New Testament his name is omitted and Jude's appears instead. It is likely that the two names refer to the same person.