Along with its companion, A Classical Dictionary of the Vulgar Tongue, the Provincial Glossary contained a large number of colloquial words that were excluded from Samuel Johnson's famous dictionary. As a young man, Grose spent time travelling throughout England and Wales on military service and made notes of the various words and phrases he encountered. The published volumes are of immense interest to modern scholars as they provide an insight into the use of dialect words across the country in the eighteenth century, some of which are still in use today.

The second half of this volume contains further information on local customs throughout England and Wales in the eighteenth century. There is an extensive section on proverbs, listed county-by-county and an additional treatise on superstitions in the country covering everything from ghosts (and how to address one), witchcraft and fairies to omens, luck and general superstitions that are still commonplace to this day.