ἀδελφός

a brother, whether born of the same two parents or only of the same father or mother, having the same national ancestor, belonging to the same people, or countryman, any fellow or man, a fellow believer, united to another by the bond of affection, an associate in employment or office, brethren in Christ, his brothers by blood, all men, apostles, Christians, as those who are exalted to the same heavenly place