zone of (or in) transition

zone of (or in) transition
Defined by the Chicago urban sociologist Ernest Burgess as an urban area, between the central business district (CBD) and outer rings of working-class and middle-class residence, containing slum housing being displaced by CBD expansion. Inhabited by the poor, ethnic minorities, and socially deviant groups. The term is broadly synonymous with what is nowadays more commonly referred to as the ‘inner city’. See also concentric zone theory.