uncongenial

The story

1. Proto-Indo-European*né
2. Proto-Indo-European*n̥-
3. Proto-Germanic*un-
4. Proto-West Germanic*un-
5. Old Englishun-
6. Middle Englishun-
7. Englishun-
8. Old Frenchcon-
9. Proto-Indo-European*ḱe?
10. Proto-Indo-European*ḱóm
11. Proto-Italic*kom
12. Proto-Italic*kom-
13. Latincon-
14. Middle Englishcon-
15. Englishcon-
16. Proto-Indo-European*ǵenh₁-
17. Latingenius
18. Proto-Indo-European*h₂el-
19. Proto-Indo-European*h₂élisder.?
20. Latingeniālis
21. Middle Frenchgénia
22. Englishgenial
23. Englishcongenial
24. English todayuncongenial

From un- + congenial.