"This Thesaurus is a collection of terms and concepts that survey the broad discourse on sustainability. Most definitions of sustainability, and the various disciplinary attempts to put it into practice, are not well suited in and of themselves for the actual achievement of sustainability. These definitions are descriptive of a future state of sustainability but lack a prescriptive process that presents how the transition from the present state of unsustainability to a future sustainability process may occur. The first section of this Thesaurus presents various attempts at defining sustainability. These abstract definitions have provided just enough information to inspire many different and often times conflicting attempts of reducing the level of unsustainability, which are categorized in the second section of this Thesaurus. Recently, social constructivists have entered the fray and have deemed sustainability 'an essentially contested concept', because of the many diverse approaches to the subject. The third section of this Thesaurus explores this debate and offers a way out of the unworkable conundrum in which social constructivist analysis places sustainability. Finally, the fourth section presents a definition of sustainability that describes an operational process through which sustainability may be achieved in practice. The information in this Thesaurus is no way exhaustive, but it largely represents the major issues and approaches of the sustainability debate. This document seeks to clarify the language surrounding sustainability, place current approaches in what the authors interpret as their proper contexts, and present a process that integrates scientific disciplines and local stakeholder participation into an ongoing balance-seeking process well suited to the achievement of sustainable city-regions. The Thesaurus is organized so that by reading the chapter headings as a first pass the reader will get a sense of the more detailed content within."