overdiagnose

The story

1. Proto-Indo-European*úp
2. Proto-Indo-European*upér
3. Proto-Germanic*uber
4. Old Englishofer-
5. Middle Englishover-
6. Englishover-
7. Proto-Indo-European*dwóh₁
8. Proto-Indo-European*trísinflu.
9. Proto-Indo-European*dwís
10. Ancient Greekδιά (diá)
11. Ancient Greekδια- (dia-)
12. Proto-Indo-European*ǵneh₃-
13. Proto-Indo-European*ǵn̥h₃sḱéti
14. Proto-Hellenic*gignṓskō
15. Ancient Greekγῐγνώσκω (gĭgnṓskō)
16. Ancient Greekδῐαγῐγνώσκω (dĭagĭgnṓskō)
17. Ancient Greekδῐᾰ́γνωσῐς (dĭắgnōsĭs)
18. Latindiagnōsis
19. Englishdiagnosisbf.
20. Englishdiagnose
21. English todayoverdiagnose

From over- + diagnose.