Quick Definition
Λεββαῖος, ου, ὁ n.m. Lebbaeus
Strong's Definition
Lebbæus, a Christian
Derivation: of uncertain origin;
KJV Usage: Lebbæus
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
Abbott-Smith Greek Lexicon
λεββαῖος, -ου, ὁ
(on the derivation, v. Dalman, Words, 50; Swete, Mk. 3:18),
Lebbæus: Mt 10:3, Mk 3:18 (WH, mg.; Θαδδαῖος, q.v., Rec., WH, txt., RV, cf. WH, App., 11, 24. In Lk 6:15, Ac 1:13, he is called Σίμων ὁ Ζηλωτής.)†
Liddell-Scott-Jones — Greek-English Lexicon
Λεββαῖος (Lebbaios) — Lebbaeus. λεββαῖος, -ου, ὁ (on the derivation, see Dalman, Words, 50; Swete, Mk., l.with), Lebbæus: Mat.10:3, Mrk.3:18 (WH, mg.; Θαδδαῖος, which see, Rec., WH, txt., RV, cf. WH, App., 11, 24. In Luk.6:15, Act.1:13, he is called Σίμων ὁ Ζηλωτής.)† (From Abbott-Smith. LSJ has no entry)