Where does “brithion” come from?

brithion (Welsh) comes from Welsh -ion, from Proto-Celtic -onā.

Ancestry of “brithion”, step by step

StepLanguageWordMeaning
1Welsh-ionPluralisation suffix
2Proto-Celtic-onā—
Every word from Proto-Celtic -onā →Every word from Welsh -ion →
brithion — Etymology, Origin & Word History | Etymology Explorer