The goal of this chapter is to specify three minimal requirements to distinguish a general from an evolutionary mismatch. This undertaking is important because the mismatch concept is used ubiquitously in everyday life as well as in several scientific contexts, including different areas of biology. Presumably, evolutionary mismatches constitute a subcategory and share some common features which characterize mismatches in a broad and general sense. But in most biological examinations, the lines between the colloquial concept and the technical term remain blurry—even within evolutionary medicine itself, as we have seen. This blending can be problematic as it inflates the number of entities that are presumed to fall under the concept of evolutionary mismatch. Can we find minimal restricting conditions that allow us to distinguish an evolutionary mismatch from a general one? The technical term needs to add further requirements to distinguish it from the general concept. To approach this problem, I start by developing three iterated definitions of mismatches in general (3.1). These definitions are not supposed to conflict with one another but capture different angles of the concept with a focus on different entities. In the next step, the focus turns away from the concept of mismatch and towards the concept of evolution (3.2). Finally, I put both semantic components back together and specify three restrictions that are necessary conditions to classify a mismatch as evolutionary (3.3). The conditions are arguably not sufficient and further specification is needed, but the delineation will suffice for the purposes of this book.