Matthew 1:2ἀδελφοὺς
Abraham was the father of Isaac, Isaac the father of Jacob, and Jacob the father of Judah and his brothers.
Mark 1:16ἀδελφὸν
As Jesus was walking beside the Sea of Galilee, He saw Simon and his brother Andrew. They were casting a net into the sea, for they were fishermen.
Luke 3:1ἀδελφοῦ
In the fifteenth year of the reign of Tiberius Caesar, while Pontius Pilate was governor of Judea, Herod tetrarch of Galilee, his brother Philip tetrarch of Ituraea and Trachonitis, and Lysanias tetrarch of Abilene,
Acts 1:14ἀδελφοῖς
With one accord they all continued in prayer, along with the women and Mary the mother of Jesus, and with His brothers.
Romans 1:13ἀδελφοί
I do not want you to be unaware, brothers, how often I planned to come to you (but have been prevented from visiting until now), in order that I might have a harvest among you, just as I have had among the other Gentiles.
1 Corinthians 1:1ἀδελφὸς
Paul, called to be an apostle of Christ Jesus by the will of God, and our brother Sosthenes,

Abbott-Smith

ἀδελφός, -οῦ, ὁ
(ἀ- copul., δελφύς, womb),
in cl., a brother, born of the same parent or parents. [In LXX (Hort, Ja., 102f.), for אָח ;]

1. lit. of a brother (Gen.4:2, al.).

2. Of a neighbour (Lev.19:17).

3. Of a member of the same nation (Exo.2:14, Deu.15:3). In NT in each of these senses (1. Mat.1:2, al.; 2. Mat.7:3; 3. Rom.9:3) and also,

4. of a fellow-Christian: 1Co.1:1, Act.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, see word). The ἀδελφοὶ τ. Κυρίου (Mat.12:46-49 13:55 28:10, Mrk.3:31-34, Luk.8:19-21, Jhn.2:12 7:3, 5 10 20:17, Act.1:14, 1Co.9:5) may have been sons of Joseph and Mary (Mayor, Ja., Intr. viff.; DB, i, 320ff.) or of Joseph by a former marriage (Lft., Gal., 252ff.; DCG, i, 232ff.), but the view of Jerome, which makes ἀ. equivalent to ἀνεψιός, is inconsistent with Greek usage. (Cremer, 66.)
(AS)

Sources: Abbott-Smith’s Manual Greek Lexicon of the New Testament (1922, public domain) and glosses from STEPBible TBESG (CC BY 4.0); STEPBible TAGNT (Greek New Testament, CC BY 4.0); the Berean Standard Bible (public domain). Reformatted by Word Study, wording unchanged. All sources and licenses.