nonbactericidal

The story

1. Proto-Indo-European*né
2. Proto-Germanic*ne
3. Proto-Indo-European*ís?
4. Proto-Indo-European*h₁óynos
5. Proto-Germanic*ainaz
6. Proto-Germanic*nainaz
7. Proto-West Germanic*nain
8. Old Englishnān
9. Middle Englishnon
10. Old Englishnān
11. Old Englishnān-
12. Middle Englishnon-
13. Englishnon-
14. Ancient Greekβακτηρία (baktēría)
15. Ancient Greekβακτήριον (baktḗrion)
16. New Latinbactērium
17. Englishbacteri(um)
18. Proto-Indo-European*kh₂eyd-
19. Proto-Indo-European*kh₂éydeti
20. Proto-Italic*kaidō
21. Latincaedō
22. Proto-Indo-European*h₂el-
23. Proto-Indo-European*h₂élisder.?
24. Englishbactericidal
25. English todaynonbactericidal

From non- + bactericidal.