Volume 4 is the final volume of the Dictionary and will be published this year after 82 years' work. Geiriadur Prifysgol Cymru is the first standard historical Welsh dictionary. It presents in alphabetical order the vocabulary of the Welsh language from the remnants of Old Welsh, through the abundant literature of the Medieval and Modern periods, to the explosion of vocabulary arising from the ever-increasing use of the language in all fields of twentieth-century life.