nonhydrodynamic

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*wed-
15. Proto-Indo-European*wódr̥
16. Proto-Hellenic*údōr
17. Ancient Greekῡ̆̔́δωρ (hū̆́dōr)
18. Ancient Greekῠ̔δρο- (hŭdro-)
19. Englishhydro-
20. Proto-Indo-European*dewh₂-
21. Proto-Hellenic*dunamai
22. Ancient Greekδῠ́νᾰμαι (dŭ́nămai)
23. Ancient Greekδύναμις (dúnamis)
24. Ancient Greekδυναμικός (dunamikós)
25. Frenchdynamique
26. Englishdynamic
27. Englishhydrodynamic
28. English todaynonhydrodynamic

From non- + hydrodynamic.