From Longman Dictionary of Contemporary Englishden of iniquityden of iniquityBAD BEHAVIOUR OR ACTIONSa place where activities that you think are immoral or evil happen – often used humorously Her mother was convinced that London was a den of iniquity. → den
Examples from the Corpus
den of iniquity• Well we've got them here now and they're after building a den of iniquity on top of your Imperial Roman artefacts.• A real den of iniquity it's divided up into several little catacombs.• Cranston loved this place, a veritable den of iniquity but one which sold good ales, fine wine and delicious food. 