ABSTRACT There is a growing body of literature arguing that we need to redefine prosperity – to move away from prosperity as economic wealth, and towards a new definition as quality of life for people and planet. While much work has been done on theories and methods for building sustainable prosperity, the process of redefinition at the level of meaning has received significantly less attention. Current arguments for redefining prosperity do not have a theory of definition despite raising multiple conceptual questions about what exactly is being redefined, what the conditions for redefining it are, and what the relationship is between redefining the word and redefining the thing. The article addresses these questions by developing a much-needed theory of definition for today’s debates on prosperity. It claims that the redefinition of prosperity is not a substitute of one definiens with another but a reconfiguration of elements in what Adorno called “a horizon of associations” at the levels of both language and social reality.