Based on: *sunto-, *swen-
A fun look at the German word for to disappear and what it has to do with wasting time, lying and vertigo... yup, they're all connected :)
verschwinden, Schwund, Geschwindigkeit, verschwenden
The core idea of the root was:
The only English family member I could find mentioned in the sources is sound in the sense of proper – like in safe and sound.
The German gesund is essentially this, but with the ge-prefix, because why not.