Used of sons of the same parent(s) (e.g. Judg. 8: 19), of related people (e.g. Deut. 23: 8, NJB), or in reference to a forgiven foe (1 Kgs. 20: 33, NRSV). In the NT it is used of a fellow Christian (1 Cor. 6: 6, NRSV marg.) and several times in Acts 15.