From Middle English bever, from Old English beofor ("beaver"), from Proto-Germanic *bebruz ("beaver") (compare West Frisian bever, Dutch bever, French bièvre, German Biber, dialectal Swedish bjur), from Proto-Indo-European *bʰébʰrus ("beaver") (compare Welsh befer, Latin fiber, Lithuanian bẽbras, Russian бобр, Avestan 𐬠𐬀𐬎𐬎𐬭𐬀, 𐬠𐬀𐬎𐬎𐬭𐬌, Sanskrit बभ्रु), from Proto-Indo-European *bʰerH- ("brown"). Related to brown and bear.