miscompartmentalization

The story

1. Proto-Indo-European*mey-?
2. Proto-Indo-European*meyth₂-
3. Proto-Germanic*missaz
4. Proto-Germanic*missa-
5. Proto-West Germanic*missa-
6. Old Englishmis-
7. Middle Englishmys-
8. Englishmis-
9. Proto-Indo-European*ḱe?
10. Proto-Indo-European*ḱóm
11. Proto-Italic*kom
12. Proto-Italic*kom-
13. Latincom-
14. Proto-Indo-European*perh₃-
15. Proto-Indo-European*pérh₃tis?
16. Proto-Italic*partis
17. Latinpars
18. Latinpartiō
19. Latinpartior
20. Latincompartīrī
21. Italiancompartire
22. Italiancompartimento
23. Middle Frenchcompartiment
24. Englishcompartment
25. Proto-Indo-European*h₂el-
26. Proto-Indo-European*h₂élisder.?
27. Englishcompartmental
28. Englishcompartmentalize
29. Englishcompartmentalization
30. English todaymiscompartmentalization

From mis- + compartmentalization.