An Irish-English Dictionary: Containing upwards of twenty thousand words that never appeared in any former Irish lexicon

An Irish-English Dictionary by Edward O’Reilly, first published in 1817, is a landmark work in Irish lexicography. It includes over 20,000 Irish words—many of which had never appeared in earlier dictionaries—making it a critical resource for scholars, historians, and language enthusiasts. O’Reilly enhances the definitions with literary citations from ancient and modern Irish texts, ensuring contextual understanding. The dictionary also draws comparisons with Welsh and Hebrew terms, enriching linguistic insight. With additional features like native plant names and a concise Irish grammar, this work stands as a foundational effort to preserve and revitalize the Irish language during a time of decline.