Where does “Røyros” come from?

Røyros (Norwegian Nynorsk) comes from Old Norse reyðr, from Old Norse rauðr, from Old English dūn, from Proto-Germanic *dūnā, from Proto-Celtic dūnom, from Proto-Indo-European dʰewh₂- — smoke; mist, haze.

Ancestry of “Røyros”, step by step

StepLanguageWordMeaning
1Old Norsereyðrrorqual, fin whale
2Old Norserauðrred
3Old Englishdūnhill, down; hill, dune; hill, mountain
4Proto-Germanic*dūnā—
5Proto-Celticdūnomstronghold, rampart
6Proto-Indo-Europeandʰewh₂-smoke; mist, haze
Every word from Proto-Indo-European dʰewh₂- →Every word from Proto-Celtic dūnom →Every word from Proto-Germanic *dūnā →