nonaerobic

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*h₂ews-
15. Proto-Indo-European*h₂ewsér
16. Proto-Hellenic*auhḗr
17. Ancient Greekἀήρ (aḗr)
18. Proto-Indo-European*gʷeyh₃-
19. Ancient Greekβίος (bíos)
20. Frenchaérobie
21. Englishaerobic
22. English todaynonaerobic

From non- + aerobic.