The title The Slum names the place where almost everything happens: the tenement João Romão builds in Botafogo, a set of little houses and washtubs for laundresses, rented by the room around a yard, which the narrator treats as a living thing. In nineteenth-century Rio de Janeiro, "cortiço" was the collective housing of poor workers.
The book itself shows the word in use. João Romão puts "São Romão Tenement" on the signboard, but the one who says the word, furious, is Miranda, when he sees his neighbor raise the wall of little houses under the windows of the townhouse: "A cortiço! Damn that shopkeeper of all the devils!". The narrator uses it too, and tells that "those three little houses" were "the starting point of the great cortiço of São Romão".
The place carries its owner's name. São Romão Tenement at first, it becomes São Romão Avenue after the fire, when it is rebuilt with verandas, lamps and more than four hundred rooms. Around it are the Cabeça-de-Gato, the rival tenement, and Miranda's townhouse, which looks down on the São Romão.
More than a setting, the tenement is the subject of the book, and so the title does not carry the name of any person. The narrator presents it being born from the mud, "like larvae in dung," and follows it waking, defending itself from the police, dividing, catching fire and remaking itself. The text does not explain the choice of the name beyond that.