This chapter advances an argument that the issues of street gang definition and group process are more closely related than anticipated. We provide the context for the selection and timeliness of these themes in comparative gang studies. As we discuss the contributions of the foregoing chapters, we reflect on the intersection of these themes insofar as aspects of group process can determine what groups get defined as street gangs. Moreover, components of gang definitions—the basic elements that comprise the way in which we understand street gangs—engage a focus on group process. We consider the implications of this work for directing further research and activity in the Eurogang Program of Research.