nonremovable

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. Proto-Italic*wre-
15. Latinre-
16. Proto-Indo-European*m(y)ewh₁-
17. Proto-Indo-European*m(y)owh₁éyeti
18. Proto-Italic*moweō
19. Latinmoveō
20. Latinremoveō
21. Old Frenchremovoir
22. Anglo-Normanremover
23. Middle Englishremoven
24. Englishremove
25. Englishremovable
26. English todaynonremovable

From non- + removable.