What does it mean to act – and to design – in times as dark and obscure as the current? This is the troubling question raised in the Bloomsbury Visual Arts book series Designing in Dark Times. In their contribution to the series, Eduardo Staszowski, associate professor of Design Strategies at Parsons The New School of Design, and Virginia Tassinari, post-doctoral fellow at Politecnico di Milano, turn to the political philosophy of German-American philosopher Hanna Arendt (1906-1975). Taking an increasingly self-destructive and distressed humanity as their point of departure, the two design researchers have invited a wide range of design scholars and practitioners to “adopt” one of Arendt’s concepts to reconsider the status and role of design today. The result is An Arendtian Lexicon, an edited volume featuring fifty-five short essays that in different ways engage terms from Arendt’s oeuvre. While alphabetically structured, the line-up of entries is not exhaustive, nor is it to be understood as a set of dictionary definitions. Instead, it constructs a clustering of Arendtian terms, central also to the contemporary design debate. Yet apart from being introduced in the editors’ introductory essay, the clusters remain opaque until the end of each entry, where they present as suggestions for cross-reading.