Where does “Niðaróss” come from?

Niðaróss (Old Norse) comes from Old Norse óss, from Proto-Germanic ansuz, from Old High German helm, from Proto-West Germanic helm, from Proto-Germanic helmaz, from Proto-Germanic halmaz, from Proto-Indo-European ḱolh₂mos, from Proto-Indo-European ḱelh₂- — to pierce, strike; to stick; prick; stab.

Ancestry of “Niðaróss”, step by step

Niðaróss traces back through two separate lines of ancestry.

via Old Norse óss

StepLanguageWordMeaning
1Old Norseóssmouth
2Proto-Germanicansuzdeity, god; name of the A-rune
3Old High Germanhelmhelmet
4Proto-West Germanichelmhelmet
5Proto-Germanichelmazhelmet
6Proto-Germanichalmazhalm; stem; stalk; straw; hay
7Proto-Indo-Europeanḱolh₂mosstalk
8Proto-Indo-Europeanḱelh₂-to pierce, strike; to stick; prick; stab

via Old Norse niðar

StepLanguageWordMeaning
1Old Norseniðar
2Old Norseniðnew moon, waning moon; time before the new moon

Words derived from “Niðaróss

Every word from Proto-Indo-European ḱelh₂-Every word from Proto-Indo-European ḱolh₂mosEvery word from Proto-Germanic halmaz