Do we really need to take 10,000 steps a day? Why tell children to look before crossing? How do we manage crowds at large events? Will scooters replace sprinting to catch the last bus? Are pedestrians drivers like any other? Does urban hiking have a bright future? Is walking the future of urban mobility? These questions, among many others, reflect important concerns related to contemporary urban life, such as road safety, the environmental crisis, the health problems associated with sedentary lifestyles, social diversity, and social exclusion. The 160 keywords in this dictionary address these issues by offering an exploration—sometimes conceptual, sometimes practical, occasionally humorous—of various fields of knowledge about walking in the city: planning and urbanism, transportation and technology, behaviors and atmospheres, tourism, literature, health, accessibility, and more. Long considered a trivial subject and a minor mode of transportation, walking is now attracting the interest of many stakeholders involved in urban life. These stakeholders, as well as students and teachers, and indeed all citizens, will find useful resources here to participate in the debates surrounding the emergence of walking as a technical and political issue.