bedevil

The story

1. Proto-Indo-European*h₁ep-
2. Proto-Indo-European*h₁éps
3. Proto-Indo-European*h₁épi
4. Proto-Indo-European*h₁pi
5. Proto-Germanic*bi
6. Proto-Germanic*bi-
7. Proto-West Germanic*bi-
8. Old Englishbe-
9. Middle Englishbi-
10. Englishbe-
11. Proto-Indo-European*dwóh₁
12. Proto-Indo-European*trísinflu.
13. Proto-Indo-European*dwís
14. Ancient Greekδιά (diá)
15. Ancient Greekδια- (dia-)
16. Proto-Indo-European*gʷelH-
17. Proto-Hellenic*gʷəlnō
18. Ancient Greekβάλλω (bállō)
19. Ancient Greekδιαβάλλω (diabállō)
20. Ancient Greekδιάβολος (diábolos)
21. Latindiabolus
22. Proto-West Germanic*diubul
23. Old Englishdēofol
24. Middle Englishdevel
25. Englishdevil
26. English todaybedevil

From be- + devil.