underadjustment

The story

1. Proto-Indo-European*h₁én
2. Proto-Indo-European*h₁entér
3. Proto-Indo-European*h₂én
4. Proto-Indo-European*dʰeh₁-?
5. Proto-Indo-European*(H)n̥dʰí
6. Proto-Indo-European*(H)n̥dʰér
7. Proto-Germanic*under
8. Proto-West Germanic*undar
9. Old Englishunder-
10. Middle Englishunder-
11. Englishunder-
12. Proto-Indo-European*h₂ey-
13. Proto-Indo-European*h₂óyu
14. Proto-Indo-European*h₂yew-
15. Proto-Indo-European*h₂yéwos
16. Proto-Italic*jowos
17. Latiniūstu
18. Old Frenchjuste
19. Frenchjuste
20. Frenchajuster
21. Frenchajustement
22. Englishadjustment
23. English todayunderadjustment

From under- + adjustment.