Welsh word elfydd comes from Proto-Indo-European *álbʰos, Proto-Indo-European *h₂elbʰós (White.)
| Dictionary entry | Language | Definition |
|---|---|---|
| *álbʰos | Proto-Indo-European (ine) | |
| *h₂elbʰós | Proto-Indo-European (ine) | White. |
| *albiyū | Proto-Celtic (cel-pro) | Britain. Alpine pasture. High mountain (especially in the Alps), alp. Luminous world, upper world, (the habitable surface of the) world. |
| *ėlβɨð | Proto-Brythonic (cel-bry-pro) | World. |
| elbid | Old Welsh (owl) | District. Earth. Land, country. World. |
| eluit | Middle Welsh (wlm) | |
| eluit, eluyd | Middle Welsh (wlm) | |
| elfydd | Welsh (cym) |