Merriam-Webster Double Click Definitions is a Chrome extension designed to enhance the browsing experience by providing instant word definitions. Users can simply double-click on any word to view its definition, streamlining the process of looking up unfamiliar terms without leaving the webpage. The extension also features a definition history that can be accessed by clicking on the extension logo, allowing users to revisit previously viewed definitions easily.

This tool utilizes definitions sourced from the Merriam-Webster's Collegiate Dictionary, ensuring reliable and authoritative information. To access its full features, users are required to obtain and enter an API key from the Merriam-Webster website. The extension is free to use, making it an accessible resource for anyone looking to improve their vocabulary or understanding of the English language while browsing online.