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*d(w)is-
- Proto-Italic*dis-
- Latindis-
- Latinputus
- Latinputō
- Latindisputo
- Latindisputābili
- Englishdisputable
- English todayundisputable
From un- + disputable.
Etymology from Wiktionary, CC BY-SA 4.0.