unipolar

The story

1. Proto-Indo-European*ís?
2. Proto-Indo-European*h₁óynos
3. Proto-Italic*oinos
4. Old Latinoinos
5. Latinūnus
6. Latinūni-
7. Englishuni-
8. Proto-Indo-European*kʷel-
9. Proto-Indo-European*kʷól-os
10. Proto-Hellenic*pólos
11. Ancient Greekπόλος (pólos)
12. Latinpolus
13. Proto-Indo-European*h₂el-
14. Proto-Indo-European*h₂élisder.?
15. Late Latinpolāri
16. Englishpolar
17. English todayunipolar

From uni- + polar.