undynamic

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*dewh₂-
9. Proto-Hellenic*dunamai
10. Ancient Greekδῠ́νᾰμαι (dŭ́nămai)
11. Ancient Greekδύναμις (dúnamis)
12. Ancient Greekδυναμικός (dunamikós)
13. Frenchdynamique
14. Englishdynamic
15. English todayundynamic

From un- + dynamic.