triperoxide

The story

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

From tri- + peroxide.