unanatomical

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*h₂en-
9. Proto-Hellenic*aná
10. Ancient Greekᾰ̓νᾰ́ (ănắ)
11. Ancient Greekἀνα- (ana-)
12. Proto-Indo-European*temh₁-
13. Ancient Greekτέμνω (témnō)
14. Ancient Greekἀνατέμνω (anatémnō)
15. Ancient Greekἀνατομή (anatomḗ)
16. Latinanatomia
17. Frenchanatomie
18. Frenchanatomique
19. Latinanatomicus
20. Englishanatomic
21. Proto-Indo-European*h₂el-
22. Proto-Indo-European*h₂élisder.?
23. Englishanatomical
24. English todayunanatomical

From un- + anatomical.