Thaddaeus

Meaning: breast

the name of one of the apostles (Mark 3:18), called "Lebbaeus" in Matt. 10:3, and in Luke 6:16, "Judas the brother of James;" while John (14:22), probably referring to the same person, speaks of "Judas, not Iscariot"

These different names all designate the same person, viz., Jude or Judas, the author of the epistle (Jude).

Also see:

• Jude
• Epistle of Jude