cyclosteroid

The story

1. Proto-Indo-European*kʷelh₁-redup.
2. Proto-Indo-European*kʷékʷlos
3. Proto-Hellenic*kʷókʷlos
4. Proto-Hellenic*kúklos
5. Ancient Greekκύκλος (kúklos)
6. Late Latincyclus
7. Middle Englishcicle
8. Englishcycle
9. Ancient Greekκύκλος (kúklos)
10. Ancient Greekκυκλῐκός (kuklĭkós)
11. Classical Latincyclicu
12. Middle Frenchcyclique
13. Frenchcyclique
14. Classical Latincyclicus
15. Englishcyclic
16. Englishcyclo-
17. Proto-Indo-European*ǵʰelh₃-
18. Proto-Hellenic*kʰolā́
19. Ancient Greekχολή (kholḗ)
20. Proto-Indo-European*ster-
21. Ancient Greekστερεός (stereós)
22. Frenchcholestérine
23. Frenchcholestéro
24. Englishcholesterol
25. Englishsterol
26. Proto-Indo-European*weyd-
27. Proto-Indo-European*wéydos
28. Proto-Hellenic*wéidos
29. Ancient Greekεἶδος (eîdos)
30. Englishsteroid
31. English todaycyclosteroid

From cyclo- + steroid.