Easton's Bible Dictionary (1897)/Brother
Brother
(2.) A near relation, a cousin (Gen. 13:8; 14:16; Matt. 12:46; John 7:3; Acts 1:14; Gal. 1:19).
(3.) Simply a fellow-countryman (Matt. 5:47; Acts 3:22; Heb. 7:5).
(4.) A disciple or follower (Matt. 25:40; Heb. 2:11, 12).
(5.) One of the same faith (Amos 1:9; Acts 9:30; 11:29; 1 Cor. 5:11); whence the early disciples of our Lord were known to each other as brethren.
(6.) A colleague in office (|Ezra 3:2; 1 Cor. 1:1; 2 Cor. 1:1).
(7.) A fellow-man (Gen. 9:5; 19:7; Matt. 5:22, 23, 24; 7:5; Heb. 2:17).
(8.) One beloved or closely united with another in affection (2 Sam. 1:26; Acts 6:3; 1 Thess. 5:1). Brethren of Jesus (Matt. 1:25; 12:46, 50: Mark 3:31, 32; Gal. 1:19; 1 Cor. 9:5, etc.) were probably the younger children of Joseph and Mary. Some have supposed that they may have been the children of Joseph by a former marriage, and others that they were the children of Mary, the Virgin's sister, and wife of Cleophas. The first interpretation, however, is the most natural.