köken: Attested in local Medieval Latin documents, as brania, at least since the 10th century. From a substrate language; perhaps from Proto-Celtic *bragnos (“rotten, faul”), either from Proto-Indo-European *bʰreHg- (“to smell, to have a strong odour”) or from Proto-Indo-European *bʰreg- (“to break”). Cf. Old Irish brén (“putrid, rotten”) and Welsh braenar (“fallow ground”).