The Scandinavian usage of tun is akin to a courtyard, or the open space between a (small and fenced in) collection of houses. Again a courtyard can be traced to

The Scandinavian usage of tun is akin to a courtyard, or the open space between a (small and fenced in) collection of houses. Again a courtyard can be traced to Middle Lower German hof, and even onwards to Proto-Germanic hufą, which is cognate with the Scandinavian word for head. And indeed if you want to say "the main part" in Danish or Norwegian you'd say hoveddelen. Hoff additionally means a royal court in Norwegian. On the other hand, the easiest cognate of this word in English is probably that of a horse hoof, which makes sense because such a tun is usually a stamped hard by both humans and their cattle.