As the construction industry embraces sustainability and the circular economy, a myriad of new terms and concepts are emerging. This rapid evolution can create confusion, especially when different stakeholders interpret terminology differently. To address this challenge, the RECONMATIC project has developed a comprehensive glossary of key terms related to construction, demolition waste, and circular economy practices. By providing clear definitions and linking related concepts, this glossary aims to foster a common understanding among all stakeholders, from contractors to policymakers. This living document will be periodically updated based on user feedback, ensuring it remains relevant and valuable for professionals and academics alike. We invite you to contribute to the continued development of this glossary by participating in our survey here. Your input will help us refine and expand the glossary, ensuring it meets the needs of the industry. Explore the glossary to enhance your understanding and application of these essential terms in your work.