Where does “угольный” come from?
угольный (Russian) comes from Russian у́гол, from Proto-Slavic ǫgъlъ, from Proto-Balto-Slavic *ángulas, from Proto-Indo-European h₂engulos, from Proto-Indo-European h₂eng- — curve, bend.
Ancestry of “угольный”, step by step
| Step | Language | Word | Meaning |
|---|
| 1 | Russian | у́гол | angle; corner |
| 2 | Proto-Slavic | ǫgъlъ | corner, angle |
| 3 | Proto-Balto-Slavic | *ángulas | — |
| 4 | Proto-Indo-European | h₂engulos | joint? |
| 5 | Proto-Indo-European | h₂eng- | curve, bend |