Easton’s Bible Dictionary

Thaddaeus

LebbaeusThaddaeus

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.

Thaddaeus in Nave’s Topical Bible2 references, arranged by theme

Easton’s Bible Dictionary (1897), public domain. Text via Theographic Bible Metadata, CC BY-SA 4.0.