isosteroidal

The story

1. Ancient Greekῐ̓́σος (ĭ́sos)
2. Englishiso-
3. Proto-Indo-European*ǵʰelh₃-
4. Proto-Hellenic*kʰolā́
5. Ancient Greekχολή (kholḗ)
6. Proto-Indo-European*ster-
7. Ancient Greekστερεός (stereós)
8. Frenchcholestérine
9. Frenchcholestéro
10. Englishcholesterol
11. Englishsterol
12. Proto-Indo-European*weyd-
13. Proto-Indo-European*wéydos
14. Proto-Hellenic*wéidos
15. Ancient Greekεἶδος (eîdos)
16. Englishsteroid
17. Proto-Indo-European*h₂el-
18. Proto-Indo-European*h₂élisder.?
19. Englishsteroidal
20. Englishiso-
21. Englishsteroid
22. Englishisosteroid
23. English todayisosteroidal

From iso- + steroidal or isosteroid + -al.