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*h₂ent-
- Proto-Indo-European*h₂énts
- Proto-Germanic*anda-
- Proto-Indo-European*swer-
- Proto-Germanic*swarjaną
- Proto-Germanic*andaswarjaną
- Old Englishandswerian
- Middle Englishansweren
- Englishanswer
- Englishanswerable
- English todayunanswerable
From un- + answerable.
Etymology from Wiktionary, CC BY-SA 4.0.