Where does “gwo-” come from?

gwo- (Middle Welsh) comes from Old Welsh guo-, from Proto-Brythonic gwo-, from Proto-Celtic uɸo-, from Proto-Indo-European upó, from Proto-Indo-European h₃ewp-.

Ancestry of “gwo-”, step by step

StepLanguageWordMeaning
1Old Welshguo-—
2Proto-Brythonicgwo-sub-, under
3Proto-Celticuɸo-sub-, under
4Proto-Indo-Europeanupóunder, below
5Proto-Indo-Europeanh₃ewp-—

Words derived from “gwo-”

Every word from Proto-Indo-European h₃ewp- →Every word from Proto-Indo-European upó →Every word from Proto-Celtic uɸo- →