Where does “вязнути” come from?

вязнути (Old East Slavic) comes from Proto-Slavic vęznǫti.

Ancestry of “вязнути”, step by step

StepLanguageWordMeaning
1Proto-Slavicvęznǫti

Words derived from “вязнути

Every word from Proto-Slavic vęznǫti
вязнути — Etymology, Origin & Word History | Etymology Explorer