The literature indicates that there are numerous definitions of strategic environmental assessment (SEA), but none of which has achieved full recognition on the part of researchers and practitioners. This study aims to compile a set of definitions that represents the amplitude of the subject matter to, on this basis, assess the conceptual evolution of SEA and to characterise the vision of the scientific community on this issue. The definitions (a total of 106) show that SEA is an evolving concept. The terms 'policies, plans and programmes', 'environmental', 'decision' and 'assess' may be considered the best descriptors of SEA. It was found that SEA maintains a strong bond with its role of impact assessment, characteristic of the first phase of its conceptual evolution. The preponderant perception of the scientific community about the definition of SEA is presented, an element that could serve as a blueprint for future discussions on the subject.
Keywords: conceptual evolution, definition, SEA, strategic environmental assessment, sustainable development, sustainability, impact assessment, environmental impact