Conceptual engineering is the method of critically assessing, improving, and replacing the concepts we use in thought and talk. Based on lectures by leading philosophers at the Conceptual Engineering Online Seminar 2020–2022, this third of three volumes focuses on applications of conceptual engineering to specific cases, including medical concepts, psychiatric concepts, concepts for social groups, concepts pertaining to the COVID-19 pandemic, environmental concepts, political concepts, and concepts in jurisdiction. It is of interest to professional philosophers with expertise in metaphilosophy or those who seek to apply the methods of conceptual engineering to issues in their own areas of specialization, as well as philosophy students who want to get acquainted with the exciting and dynamic methodological developments of their discipline. This volume includes chapters by Roberto Casati and colleagues, Rachel Cooper, Elisabetta Lalumera, Ethan Landes, Genoveva Martí & Lorena Ludeña-Ramírez, Kevin Reuter & Lucien Baumgartner, and Katherine Ritchie.