Synonyms/Hypernyms (Ordered by Estimated Frequency) of noun dungeon

2 senses of dungeon

Sense 1
keep, donjon, dungeon -- (the main tower within the walls of a medieval castle or fortress)
       => stronghold, fastness -- (a strongly fortified defensive structure)

Sense 2
dungeon -- (a dark cell (usually underground) where prisoners can be confined)
       => cell, jail cell, prison cell -- (a room where a prisoner is kept)