rookery

1. (by extension) A crowded tenement.Examples: "Lord John Roxton and I turned down Vigo Street together and through the dingy portals of the famous aristocratic rookery."; "Spying flames vomiting from a Manhattan tenement one night last week, a scavenging junkman named Roderick Good turned in an alarm. In their beds in the five-story rookery lay more than 100 tenants."; "The squares near Ladbroke Grove station ... never managed to attract the kind of people for which they were designed and sank rapidly into multiple occupation, becoming almost as bad as the nearby rookeries of north-west Kensington."broadly

2. (British, historical, by extension) A place where criminals congregate, often an area of a town or city.Examples: "The Flower and Dean St rookery had been home to many of those who lived at least partly by street crime."; "These rookeries sustained criminal social systems that provided schooling in crime for the young and newcomers."; "In the Victorian imagination, crime and the criminal class were always associated with rookeries, the dense slum areas in which criminals were said to live."Synonyms: slumBritishbroadlyhistorical

3. (military, slang, obsolete) That part of the barracks occupied by subalterns.obsoleteslang