isoindole

The story

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

From iso- + indole.