The story
- Proto-Indo-European*né
- Proto-Indo-European*n̥-
- Proto-Germanic*un-
- Proto-West Germanic*un-
- Old Englishun-
- Middle Englishun-
- Englishun-
- Proto-Indo-European*dwóh₁
- Proto-Indo-European*trísinflu.
- Proto-Indo-European*dwís
- Ancient Greekδιά (diá)
- Ancient Greekδια- (dia-)
- Proto-Indo-European*ǵneh₃-
- Proto-Indo-European*ǵn̥h₃sḱéti
- Proto-Hellenic*gignṓskō
- Ancient Greekγῐγνώσκω (gĭgnṓskō)
- Ancient Greekδῐαγῐγνώσκω (dĭagĭgnṓskō)
- Ancient Greekδῐᾰ́γνωσῐς (dĭắgnōsĭs)
- Latindiagnōsis
- Englishdiagnosisbf.
- Englishdiagnos(e)
- Englishdiagnosable
- English todayundiagnosable
From un- + diagnosable.
Etymology from Wiktionary, CC BY-SA 4.0.