The term claret is most common in the United Kingdom. People from the United States usually call it "red Bordeaux" or just "Bordeaux".
It has been coined from the clairet, a now uncommon dark rosé which was the most common style of wine exported from Bordeaux until the 18th century. Claret is a protected name within the European Union for describing a red Bordeaux wine; it was accepted after the British wine trade demonstrated over 300 years' usage of the word.
The name Claret is occasionally used in the United States as a semi-generic label for any red wine in a style similar to that of Bordeaux. However, the usual practice today is to label wines by the grape variety or varieties from which they are made.
The French themselves do not use the term Claret, except for export purposes.