Etymology. The word dungeon comes from French donjon (also spelled dongeon), which means "keep", the main tower of a castle.

What is a donjon meaning?

: a massive inner tower in a medieval castle — see castle illustration.

What is the difference between donjon and dungeon?

As nouns the difference between donjon and dungeon

is that donjon is the fortified tower of a motte or early castle; a keep while dungeon is an underground prison or vault, typically built underneath a castle.