Carmarthenshire is a county located in the southwest part of Wales. The word "Carmarthenshire" can be replaced or defined with various synonyms. For instance, one could refer to it as a Welsh region, or alternatively, a Welsh county. In addition to being a county, Carmarthenshire is also a historic and cultural area of Wales, with a rich Celtic heritage. Another synonym for Carmarthenshire is Dyfed, which is an ancient kingdom that existed in Wales. Some other words that can be used interchangeably with Carmarthenshire include 'Llanelli', 'Carmarthen', and 'Saint Clears'. Lastly, Carmarthenshire is known as the "Garden of Wales," which is an ideal synonym for its stunning landscape and abundant natural beauty.