From Proto-Italic *alβos, from Proto-Indo-European *albʰós. Cognates include Umbrian 𐌀𐌋𐌚𐌖 (alfu), Ancient Greek ἀλφός (alphós, “whiteness, white leprosy”), Hittite 𒀠𒉺𒀸 (alpas, “cloud”), Middle Welsh elbid (“world”), English elf, and Russian ле́бедь (lébedʹ, “swan”).