rediagnose

The story

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

From re- + diagnose.