Where does “Guorthegirnus” come from?

Guorthegirnus (Latin) comes from Old Welsh Guorthigirn, from Proto-Brythonic *Gworθɨɣern, from Proto-Celtic Uɸortigernos, from Proto-Celtic uɸor-, from Proto-Indo-European upér, from Proto-Indo-European upó, from Proto-Indo-European h₃ewp-.

Ancestry of “Guorthegirnus”, step by step

StepLanguageWordMeaning
1Old WelshGuorthigirn
2Proto-Brythonic*Gworθɨɣern
3Proto-CelticUɸortigernos
4Proto-Celticuɸor-over, super-
5Proto-Indo-Europeanupérabove; over
6Proto-Indo-Europeanupóunder, below
7Proto-Indo-Europeanh₃ewp-
Every word from Proto-Indo-European h₃ewp-Every word from Proto-Indo-European upóEvery word from Proto-Indo-European upér