unacrobatic

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. Proto-Indo-European*h₂eḱ-
9. Proto-Indo-European*h₂eḱrós
10. Proto-Hellenic[Term?]
11. Ancient Greekᾰ̓́κρος (ắkros)
12. Proto-Indo-European*gʷem-
13. Proto-Indo-European*gʷm̥yéti
14. Proto-Hellenic*gʷəňňō
15. Proto-Indo-European*gʷeh₂-
16. Proto-Hellenic*égʷēn
17. Ancient Greekβαίνω (baínō)
18. Ancient Greekβᾰτός (bătós)
19. Ancient Greekἀκροβάτης (akrobátēs)
20. Frenchacrobate
21. Englishacrobat
22. Englishacrobatic
23. English todayunacrobatic

From un- + acrobatic.