The word "Wales" is derived from the descriptive name for it's people, The Welsh. (The opposite way that country names and ethnic group names usually develop) "Welsh" is a collective name for "Foreigners" in the certain ancient languages. In ancient times, when the european word still revolved mostly around Rome (although when it was in decline), the name was used by Germanic and Celtic tribes in cross-cultural communication with the Romans to describe all celts and germanic tribes that were not themselves. This word was adopted by the Romans who used it to describe all celtic and germanic tribes who were not roman, and slowly became more and more specific to the Celtic tribes from southern Britannia. When the Saxons, and later the Angles invaded what is now England (have difficulties in advancing into modern day wales), this displaced all of the people who in the areas who had previously been known as Welsh by the Romans, meaning that Wales was now the only place in the world in which it's inhabitants were known as the Welsh. This name persisted through centuries and was passed back from the romans to the Angles and Saxons. The anglo-saxon difficulties in conquering modern day wales combined with the definition of all of those people that had remained unconquered by them in modern day england as "welsh" created a border between the welsh lands and the anglo-saxon lands, creating Wales.

So in short, a modern day translation for Wales would be "Not Italy" ... I can't help be reminded of Bladrick's definition of "Dog"