noun, plural arch·duch·ies.
Examples from the Web for archduchy
Meanwhile Styria and Carinthia Austria created an archduchy.
The revenues of the archduchy were some four millions of dollars.The Empire of Austria; Its Rise and Present Power|John S. C. Abbott
Transleithan, trans-lī′than, adj. beyond the Leitha, the boundary river between the archduchy of Austria and Hungary.
The archduchy of Austria was, and Hungary was not, German, in the reign of the emperors.Down the Rhine|Oliver Optic