1. (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.

2. (n.) A squalid place of resort; a wretched dwelling place; a haunt; as, a den of vice.

3. (n.) Any snug or close retreat where one goes to be alone.

4. (n.) A narrow glen; a ravine; a dell.

5. (v. i.) To live in, or as in, a den.

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