eudiagnostic

The story

1. Proto-Indo-European*h₁wes-
2. Proto-Indo-European*h₁wésus?
3. Proto-Indo-European*h₁es-?
4. Proto-Indo-European*h₁su-
5. Proto-Hellenic*ehu-
6. Ancient Greekἐΰς (eǘs)
7. Ancient Greekεὖ (eû)
8. Englisheu-
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. English todayeudiagnostic

From eu- + diagnostic.