monodimensionally

The story

1. Proto-Indo-European*men-
2. Proto-Hellenic*mónwos
3. Ancient Greekμόνος (mónos)
4. Ancient Greekμονο- (mono-)
5. Englishmono-
6. Proto-Indo-European*dwóh₁
7. Proto-Indo-European*trísinflu.
8. Proto-Indo-European*d(w)is-
9. Proto-Italic*dis-
10. Latindis-
11. Proto-Indo-European*med-
12. Proto-Indo-European*meh₁-
13. Proto-Italic*mētis
14. Latinmētior
15. Latindīmētior
16. Latindīmēnsiō
17. Englishdimension
18. Proto-Indo-European*h₂el-
19. Proto-Indo-European*h₂élisder.?
20. Englishdimensional
21. Englishmonodimensional
22. Proto-Indo-European*leyg-
23. Proto-Germanic*līką
24. English todaymonodimensionally

From monodimensional + -ly.