Much attention has been paid to the contested concept of “social enterprise”. A wide variety of organisational types have had the label attributed to them or have tried to claim the label for themselves. Existing academic literature provides a bewildering array of definitions and explanations for the emergence of social enterprise. This conceptual confusion is because social enterprise is a fluid and contested concept constructed by different actors promoting different discourses connected to different organisational forms and drawing upon different academic theories. This article makes sense of these different social enterprise forms, academic explanations and policy and practitioner discourses. Using the example of England, where social enterprise has been heavily promoted and supported as a site for policy intervention, an analysis of how the meanings of social enterprise have evolved and expanded over time is provided. This demonstrates that the language of social enterprise was initially developed as a way of promoting co-operative and mutual models of public and private enterprise. Its meaning expanded as other actors adopted the language to compete for policy attention and resources. Policy makers deliberately kept the definition loose to allow for the inclusion of almost any organisation claiming to be a social enterprise. This allowed them to amalgamate the positive characteristics of the different organisational forms, and so claim to be addressing a wide range of social problems using social enterprise as a policy tool.