The story
PIE word *bʰréh₂tēr Etymology tree Proto-Indo-European *bʰréh₂tēr Proto-Germanic *brōþēr Proto-West Germanic *brōþer Old English brōþor Middle English brother English brotherder. English bruvverclip. English bruv Clipping of bruvver.
Etymology from Wiktionary, CC BY-SA 4.0.