prediagnostically

The story

1. Proto-Indo-European*per-
2. Proto-Indo-European*preh₂-
3. Proto-Indo-European*préh₂i?
4. Proto-Italic*prai
5. Proto-Italic*prai-
6. Latinprae-
7. Middle Englishpre-
8. Englishpre-
9. Proto-Indo-European*dwóh₁
10. Proto-Indo-European*trísinflu.
11. Proto-Indo-European*dwís
12. Ancient Greekδιά (diá)
13. Ancient Greekδια- (dia-)
14. Proto-Indo-European*ǵneh₃-
15. Proto-Indo-European*ǵn̥h₃sḱéti
16. Proto-Hellenic*gignṓskō
17. Ancient Greekγῐγνώσκω (gĭgnṓskō)
18. Ancient Greekδῐαγῐγνώσκω (dĭagĭgnṓskō)
19. Ancient Greekδῐᾰ́γνωσῐς (dĭắgnōsĭs)
20. Ancient Greekδῐᾰ- (dĭă-)
21. Proto-Indo-European*ǵneh₃-
22. Proto-Indo-European*ǵneh₃tis
23. Ancient Greekγνῶσις (gnôsis)
24. Ancient Greekγνωστῐκός (gnōstĭkós)
25. Ancient Greekδῐαγνωστῐκός (dĭagnōstĭkós)
26. Englishdiagnostic
27. Proto-Indo-European*h₂el-
28. Proto-Indo-European*h₂élisder.?
29. Proto-Indo-European*leyg-
30. Proto-Germanic*līką
31. Englishdiagnostically
32. English todayprediagnostically

From pre- + diagnostically.