bipolaron

The story

1. Proto-Indo-European*dwóh₁
2. Proto-Indo-European*dwi-
3. Proto-Italic*dwi-
4. Latinbi-
5. Englishbi-
6. Proto-Indo-European*kʷel-
7. Proto-Indo-European*kʷól-os
8. Proto-Hellenic*pólos
9. Ancient Greekπόλος (pólos)
10. Latinpolus
11. Proto-Indo-European*h₂el-
12. Proto-Indo-European*h₂élisder.?
13. Late Latinpolāri
14. Englishpolar
15. Ancient Greekἤλεκτρον (ḗlektron)
16. Latinēlectrum
17. New Latinēlectricus
18. Englishelectric
19. Proto-Indo-European*h₁ey-
20. Proto-Indo-European*h₁éyti
21. Proto-Hellenic*éimi
22. Ancient Greekἰόν (ión)
23. Englishion
24. Englishelectronbf.
25. Englishpolaron
26. English todaybipolaron

From bi- + polaron.