from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A place of immoral behavior, usually of a sexual type.
The origin of the term can be traced back to the New Testament of the Bible. In both Gospel of Mark and Matthew, Jesus condemns those who have been using the sacred temple as a marketplace, proclaiming that they have "made it a den of thieves." To this day, writers use the word "den" to mean a place where iniquitous activities are carried out. (Wiktionary)