Where does “dornioù” come from?

dornioù (Breton) comes from Breton dorn, from English durn, from Ukrainian дурний, from Proto-Slavic *durьnъ — stupid, crazy.

Definitions

Ancestry of “dornioù”, step by step

StepLanguageWordMeaning
1Bretondornhand
2Englishdurndarn; damn; Darn; damned; extremely; Rhoticized...
3Ukrainianдурнийstupid
4Proto-Slavic*durьnъstupid, crazy
Every word from Proto-Slavic *durьnъ →Every word from Ukrainian дурний →Every word from English durn →