Dungeon (noun)

1. A strong room or cell, typically underground, in a castle or prison.
2. A place of confinement, especially one underground.
3. A dark, underground chamber or cellar.

Origin:

Middle english: from old french donjon, from latin dominium "lord"s house", from dominus "lord".

Examples:

1. The prisoner was thrown into the dungeon and left to rot.
2. The old castle had a dungeon with damp walls and iron bars.
3. The dungeon was a dark and dingy place, with no light or ventilation.
4. The king ordered the traitor to be locked up in the dungeon.
5. The dungeon was a place of torture, with instruments of punishment scattered around the room.