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*h₂éd
- Proto-Italic*ad
- Proto-Italic*ad-
- Latinad-
- Proto-Indo-European*h₂ep-
- Proto-Indo-European*h₂ptós
- Proto-Italic*aptos
- Latinaptus
- Proto-Indo-European[Term?]
- Proto-Italic*apjō
- Latinapiō
- Latinaptō
- Latinadaptō
- Middle English*adapten
- Englishadapt
- Englishadaptable
- English todayunadaptable
From un- + adaptable.
Etymology from Wiktionary, CC BY-SA 4.0.