polythiophene

The story

1. Proto-Indo-European*pleh₁-
2. Proto-Indo-European*polh₁ús
3. Ancient Greekπολῠ́ς (polŭ́s)
4. Englishpoly-
5. Proto-Indo-European*dʰewh₂-der.?
6. Ancient Greekθέειον (théeion)
7. Ancient Greekθεῖον (theîon)
8. Englishthio-
9. Proto-Indo-European*bʰeh₂-
10. Proto-Indo-European*bʰh₂nyéti
11. Proto-Hellenic*pʰáňňō
12. Ancient Greekφαίνω (phaínō)
13. Frenchphène
14. Englishphene
15. Englishthiophene
16. English todaypolythiophene

From poly- + thiophene.