Where does “Guorthigirn” come from?

Guorthigirn (Old Welsh) comes 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 “Guorthigirn”, step by step

StepLanguageWordMeaning
1Proto-Brythonic*Gworθɨɣern—
2Proto-CelticUɸortigernos—
3Proto-Celticuɸor-over, super-
4Proto-Indo-Europeanupérabove; over
5Proto-Indo-Europeanupóunder, below
6Proto-Indo-Europeanh₃ewp-—

Words derived from “Guorthigirn”

Every word from Proto-Indo-European h₃ewp- →Every word from Proto-Indo-European upó →Every word from Proto-Indo-European upér →