бөөр • (böör) (Mongolian spelling ᠪᠥᠭᠡᠷᠡ)
From Middle Mongolian [script needed] (bo'ere), from Proto-Mongolic *böɣere (“kidney(s); testicle(s)”). Akin to Proto-Turkic *bögür (“kidney(s)”), compare Turkish böğür (“flank, side”), Yakut бүөр (büör, “kidney”).