The concept of fragility, which was initially born in the security arena, has been gaining increasing relevance in the development discourse over the past few years. However, fragility still remains a fuzzy and elusive term. This paper identifies three main sets of definitions of fragility, which substantially differ in their focus and breadth. The limited consensus that is found in the academic and policy-oriented literature suggests that the analytical salience and the operational value-added of this concept still remain unclear, as substantial differences arise when it comes to the design of development policies.