1. A close dark place of confinement, usually underground.

2. To confine in a dungeon. See Donjon.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• dongeon,
• dugon,
• dungens,
• dugeon,
• dunken,
• dungin,
• dungoons,
• dungions,
• pungen,
• duncon,
• doneon,
• doungen,
• dungeouns,
• dungen,
• dunegon,
• dungoen,
• doungon,
• dungon,
• dundeon,
• dungons

• dunnigan,
• Dunnagan,
• dunson,
• dungan.

The adverb for the word "dungeon" would be "dungeonishly" or "dungeon-like".

The adjective form of the word "dungeon" is "dungeonous". However, it is worth noting that this term is not commonly used.

The plural of the "dungeon" can be the "dungeons".

The singular of the "dungeon" can be the "dungeon".