Quick Definition
Θαδδαῖος, ου, ὁ n.m. Thaddaeus
Strong's Definition
of uncertain origin; Thaddaeus, one of the Apostles
KJV Usage: Thaddaeus
UBS Dictionary of the Greek New Testament
UBS Dictionary of the Greek New Testament © United Bible Societies, licensed CC BY-SA 4.0.
Thayer's Greek Lexicon
Θαδδαῖος, -ου, 6, (IN, perh. large-hearted or courageous, although it has not been shown that 14 equiv. to the Hebr. 1w can mean pectus as well as mamma; [some would connect the terms by the fact that the ‘child of one’s heart’ may be also described as a ‘bosom-child’; but see B.D. s. vy. Jude]), Thaddeus, a surname of the apostle Jude; he was also called Lebbeus and was the brother of James the less: Mt.x.3 RGLTr WH; Mk. iii. 18. [Cf. B. D. 5. v.; Keil on Mt.1.c.; WH. App. p- 11. The latter hold the name Λεββαῖος to be due to an early attempt to bring Levi (Aeveis) the publican (Lk. v. 27) within the Twelve. ]
Mounce Concise Greek Dictionary
Θαδδαῖος Thaddaios 2x
Thaddaeus, pr. name, Mt. 10:3; Mk. 3:18*
Abbott-Smith Greek Lexicon
Θαδδαῖος, -ου, ὁ (Aram. תַּדִאַי, תַּדַּי), Thaddæus: Mt 10:3, Mk 3:18 (WH, mg., Λεββαῖος, q.v.).†
Liddell-Scott-Jones — Greek-English Lexicon
Θαδδαῖος (Thaddaios) — Thaddaeus. Θαδδαῖος, -ου, ὁ (Aram. תּדִאַי, תַּדַּי), Thaddæus: Mat.10:3, Mrk.3:18 (WH, mg., Λεββαῖος, which see).† (From Abbott-Smith. LSJ has no entry)