noun
duchy
DUCH-ee/ˈdʌtʃi/
The territorial authority of a duke or duchess.
The duke studies a map of his duchy, including its towns and farmland.

Etymology
Duché named a duke's territory, linking the land to its ruler's title. That title ultimately meant 'leader'; the English word retains the territorial sense and also covers land ruled by a duchess.
In context
Luxembourg, an independent and sovereign nation with a history dating back as far as the 8th century, is the only remaining independent grand duchy, with HRH the Grand Duke Henri I (dynasty of Luxembourg-Nassau) as its head of state
More examples
- The river marks the eastern border of the duchy.
- The duke divides his duchy between his two children.
- The map shows several duchies within the empire.
Forms
duchy · duchies
duke noun — A high-ranking nobleman who may rule territory.
duchess noun — A female duke or a duke's wife.
Similar words
- principality
- A territory ruled by a prince rather than a duke.
- kingdom
- A realm ruled by a king or queen, not a duke.