Where does “Ruginoasa” come from?

Ruginoasa (English) comes from Romanian Ruginoasa, from Romanian ruginos, from Romanian rugină, from Latin aerūgina, from Latin aerūgō, from Latin aes, from Proto-Italic aos, from Proto-Italic ajos — a metal, copper, bronze.

Ancestry of “Ruginoasa”, step by step

StepLanguageWordMeaning
1RomanianRuginoasa
2Romanianruginosrusty, rusted, oxidated
3Romanianruginărust
4Latinaerūgina
5Latinaerūgōrust of copper, verdigris
6Latinaesmoney, pay, fee, fare; copper, bronze, brass;...
7Proto-Italicaosbronze, copper
8Proto-Italicajos
9Proto-Indo-Europeanh₂éyosa metal, copper, bronze
Every word from Proto-Indo-European h₂éyosEvery word from Proto-Italic ajosEvery word from Proto-Italic aos