peroxidation

The story

1. Proto-Indo-European*per-der.?
2. Proto-Indo-European*pér
3. Proto-Italic*per
4. Latinper
5. Proto-Indo-European*per-
6. Proto-Italic*peri-
7. Latinper-
8. Englishper-
9. Proto-Indo-European*h₂eḱ-der.?
10. Ancient Greekὀξύς (oxús)
11. Proto-Indo-European*ǵenh₁-
12. Proto-Indo-European*ǵénh₁os
13. Proto-Hellenic*génos
14. Ancient Greekγένος (génos)
15. Frenchoxygène
16. Proto-Indo-European*h₂eḱ-
17. Proto-Indo-European*h₂eḱéh₁yeti
18. Proto-Italic*akēō
19. Latinaceō
20. Proto-Indo-European*dʰeh₁-
21. Latinacidu
22. Frenchacide
23. Frenchoxide
24. Englishoxide
25. Englishperoxide
26. English todayperoxidation

From peroxide + -ation.