A settlement, region, or collection of castles; the domain controlled by a castle or group of castles.
From castle with the suffix -ery (place where something is made or found, or a collection of things). This rare word follows the pattern of words like 'forgery' and 'pottery,' though it's largely obsolete.
This word is almost extinct—you won't find it in modern dictionaries—but it reveals how medieval writers tried to describe castle-dominated landscapes and the feudal territories they controlled!
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