also exists in the name of the city of Stuttgart: originally a place for horses (studs, specifically). Sorry I can't recall where I read that.

Also related, of course, are the words "yard", "guard," and "ward." The letter 'g' is related to both 'y' and 'w'. In OE, the 'g' as 'y' sound was already present (so that "geard" was pronounced very close to modern "yard"). The 'g' and 'w' being cognate can also be seen in the relation between, e.g., "Gallic" and "Welsh", I have been told.

Granted, this doesn't really illuminate the "Peoples of Middangeard" like the title says, but it's about their name at least!