nondimensional

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-Indo-European*dwóh₁
15. Proto-Indo-European*trísinflu.
16. Proto-Indo-European*d(w)is-
17. Proto-Italic*dis-
18. Latindis-
19. Proto-Indo-European*med-
20. Proto-Indo-European*meh₁-
21. Proto-Italic*mētis
22. Latinmētior
23. Latindīmētior
24. Latindīmēnsiō
25. Englishdimension
26. Proto-Indo-European*h₂el-
27. Proto-Indo-European*h₂élisder.?
28. Englishdimensional
29. English todaynondimensional

From non- + dimensional.