This work is a copy of the 3rd edition of John Walter’s English-Welsh dictionary, first published in 15 parts 1770-1794. The first 14 parts were published by Rhys Thomas at the Cowbridge Press, the first printing press in Glamorgan. Walters, a Welsh cleric and classical scholar, first demonstrated his interest in the history of the Welsh language with his publication A Dissertation on the Welsh language (1771), and it was appended to all editions of his dictionary. This was based on the unpublished manuscript of an English-Welsh dictionary by William Gambold, completed in 1722. Walters’ aim was to enable Welsh writers to discuss all areas of scholarship in Welsh, and thus his dictionary derived its contents from literary as well as spoken sources of Welsh. He also coined several new words, many of which are still in use today.