donjon

American  

[duhn-juhn, don-] / ˈdʌn dʒən, ˈdɒn- /

noun

1. the inner tower, keep, or stronghold of a castle.

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donjon British  

/ ˈdʌndʒən, ˈdɒn- /

noun

1. Also called: dungeon.  the heavily fortified central tower or keep of a medieval castle

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Etymology

Origin of donjon

Variant of dungeon

Example Sentences

However, both donjon and dungeon originally referred to and still refer to, secondarily, a castle keep.

From Slate • Sep. 25, 2017

Turning to Google, I learned that the English word dungeon emerged several centuries ago from the French donjon, which in turn is thought to have descended from dominio, which is Latin for lord or master.

From Slate • Sep. 25, 2017

Oldest part of the grim little hamlet was a "broch tower": a crude donjon keep.

From Time Magazine Archive

Approached thus, the massive donjon tower, set on a cliff and looming a hundred and twenty feet into the air, is most impressive.

From The Charm of Ireland by Stevenson, Burton Egbert

And when Arthur went up into the donjon tower, the wolf held him by the lap of his garment; and when King Arthur was seated, the wolf lay at his feet.

From Tales from the Old French by Various