From Proto-Germanic*bōkijǭ, from Proto-Indo-European*bʰeh₂ǵos. Cognate with Old Saxon bōka, Dutch beuk, Old High German buohha (German Buche), Old Norse bók (Swedish bok). The Indo-European root is also the source of Ancient Greek φηγός(phēgós, “oak”), Latin fāgus(“beech”), Russian бузина(buzina, “elder-tree”).