ἈΔΕΛΦΌΣ: ἀδελφός, -οῦ, ὁ [ (< ἀ- copul., δελφύς, womb), ] in cl., a brother, born of the same parent or parents. [In LXX (Hort, Ja., 102 f.), for אָח;] 1. . lit. of a brother (Ge 4:2, al.).
2. . Of a neighbour (Le 19:17).
3. . Of a member of the same nation (Ex 2:14, De 15:3). In NT in each of these senses (1. Mt 1:2, al.; 2. Mt 7:3; 3. Ro 9:3) and also, 4. . of a fellow-Christian: I Co 1:1, Ac 9:30. This usage finds illustration in π., where ἀ. is used of members of a pagan religious community (M, Th., I, 1:4; MM, VGT, s.v.). The ἀδελφοὶ τ. Κυρίου (Mt 12:46-49 13:55 28:10, Mk 3:31-34, Lk 8:19-21, Jo 2:12 7:3, 5 10 20:17, Ac 1:14, I Co 9:5) may have been sons of Joseph and Mary (Mayor, Ja., Intr. viff.; DB, i, 320 ff.) or of Joseph by a former marriage (Lft., Gal., 252ff.; DCG, i, 232 ff.), but the view of Jerome, which makes ἀ. equivalent to ἀνεψιός, is inconsistent with Greek usage. (Cremer, 66.)