indolyl

The story

1. Proto-Indo-Iranian*síndʰuš
2. Sanskritसिन्धु॑ (síndhu)
3. Old Persian𐏃𐎡𐎯𐎢𐏁 (hiⁿdūš)
4. Ancient GreekἸνδός (Indós)
5. Ancient GreekἸνδία (Indía)
6. Ancient GreekἸνδικός (Indikós)
7. LatinIndicu
8. Spanishíndico
9. Spanishíndigo
10. Portugueseendego
11. Spanishíndigo
12. Dutchindigo
13. Englishind(igo)
14. Proto-Hellenic*élaiwon
15. Ancient Greekἔλαιον (élaion)
16. Latinole(um)
17. Englishindole
18. Proto-Indo-European*swel-der.?
19. Ancient Greekῡ̔́λη (hū́lē)
20. English todayindolyl

From indole + -yl.