ABSTRACT This article presents a definitional structure for the notion of ‘proxy war’ organised around three components: (1) a material-constitutive feature, (2) a processual feature and (3) a relational feature. First, the article evaluates the multiple usages of the term of ‘proxy war’ in light of its contested character. Second, it proposes a way of making sense of the literature’s conceptual turmoil by analysing the different attempts at defining the notion. To this end, it adds an important link to the methodology of concept analysis, namely the ‘semantic field’, which it re-introduces as a heuristic to identify ‘military intervention’ as a root concept for defining proxy wars. The article does so by identifying a type of semantic relationship between ‘proxy war’ and ‘military intervention’, namely sub-type inclusion.