oxosteroid

The story

1. Proto-Indo-European*h₂eḱ-der.?
2. Ancient Greekὀξύς (oxús)
3. Proto-Indo-European*ǵenh₁-
4. Proto-Indo-European*ǵénh₁os
5. Proto-Hellenic*génos
6. Ancient Greekγένος (génos)
7. Frenchoxygène
8. Englishoxygen
9. Englishoxo-
10. Proto-Indo-European*ǵʰelh₃-
11. Proto-Hellenic*kʰolā́
12. Ancient Greekχολή (kholḗ)
13. Proto-Indo-European*ster-
14. Ancient Greekστερεός (stereós)
15. Frenchcholestérine
16. Frenchcholestéro
17. Englishcholesterol
18. Englishsterol
19. Proto-Indo-European*weyd-
20. Proto-Indo-European*wéydos
21. Proto-Hellenic*wéidos
22. Ancient Greekεἶδος (eîdos)
23. Englishsteroid
24. English todayoxosteroid

From oxo- + steroid.