What medieval words begin with the letters X Y Z?

Zaduzbina:

An obligation for one's soul; each Nemanjic ruler of Serbia built a monastery as his zaduzbina.

(Fine, John V.A. Jr. The Late Medieval Balkans, 627)

Zbor:

A tribal assembly.

(Fine, John V.A. Jr. The Late Medieval Balkans, 627)

Zupa: [zupanija]

A territorial unit (roughly equivalent to a county) in Croatia, Bosnia, and Serbia.

(Fine, John V.A. Jr. The Late Medieval Balkans, 627)

Zupan:

The lord of a county - a count.

(Fine, John V.A. Jr. The Late Medieval Balkans, 627)