(Spanish) form of Carmel, altered by folk etymology to the form of the Latin word carmen ‘song’. It is now sometimes found as a given name in the English-speaking world, in spite of, or perhaps because of, its association with the tragic romantic heroine of Bizet's opera Carmen (1875), based on a short story by Prosper Mérimée.
Spanish (Galván): from a medieval personal name. This is in origin the Latin name Galbanus (a derivative of the Roman family name Galba, of uncertain origin). However, it was used in a number of medieval romances as an equivalent of the Celtic name Gawain (see Gavin), and it is probably this association that was mainly responsible for its popularity in the Middle Ages.