Definition of: brother

(bruth′ər) noun plural broth·ers or Archaic breth·ren
1. A male person having the same parent as another or others. Sons of the same two parents are full or whole brothers; those having only one parent in common are half-brothers.
2. A person of the same descent, profession, trade, company, etc., with another or others; one having the same racial heritage; a kinsman.
3. A fellow human being.
4. One closely united with another or others by religious, political, or family bond.
5. One of a male religious order; a monk.
6. U.S. Colloq. A black man; a fellow black.
—v.t. To treat or address as a brother. [OE brōthor]