retrodiagnose

The story

1. Proto-Italic*wre-
2. Latinre-
3. Latinretrō
4. Englishretro-
5. Proto-Indo-European*dwóh₁
6. Proto-Indo-European*trísinflu.
7. Proto-Indo-European*dwís
8. Ancient Greekδιά (diá)
9. Ancient Greekδια- (dia-)
10. Proto-Indo-European*ǵneh₃-
11. Proto-Indo-European*ǵn̥h₃sḱéti
12. Proto-Hellenic*gignṓskō
13. Ancient Greekγῐγνώσκω (gĭgnṓskō)
14. Ancient Greekδῐαγῐγνώσκω (dĭagĭgnṓskō)
15. Ancient Greekδῐᾰ́γνωσῐς (dĭắgnōsĭs)
16. Latindiagnōsis
17. Englishdiagnosisbf.
18. Englishdiagnose
19. English todayretrodiagnose

From retro- + diagnose.