Where does “Ruginescu” come from?

Ruginescu (Romanian) comes from Romanian rugină, from Latin aerūgina, from Latin aerūgō, from Latin aes, from Proto-Italic aos, from Proto-Italic ajos, from Proto-Indo-European h₂éyos — a metal, copper, bronze.

Ancestry of “Ruginescu”, step by step

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