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*ḱe?
- Proto-Indo-European*ḱóm
- Proto-Italic*kom
- Proto-Italic*kom-
- Latincōn-
- Proto-Indo-European*streyg-
- Proto-Indo-European*strinégti
- Proto-Italic*stringō
- Proto-Indo-European*strengʰ-
- Proto-Indo-European*stréngʰeti
- Proto-Italic*strengō
- Latinstringō
- Latincōnstringō
- Old Frenchconstreindre
- Middle Englishconstreinen
- Englishconstrain
- Englishconstrainable
- English todayunconstrainable
From un- + constrainable.
Etymology from Wiktionary, CC BY-SA 4.0.