Den(n.)
- A small cavern or hollow place in the side of a hill, or among rocks; esp., a cave used by a wild beast for shelter or concealment; as, a lion's den; a den of robbers.
Den(n.)
- A squalid place of resort; a wretched dwelling place; a haunt; as, a den of vice.
Den(n.)
- Any snug or close retreat where one goes to be alone.