Pet form of Cynthia or, less often, of Lucinda, now very commonly used as a given name in its own right, especially in North America. It has sometimes been taken as a short form of the name of the fairytale heroine Cinderella, which is in fact unrelated (being from French Cendrillon, a derivative of cendre ‘cinders’).
Spanish: nickname for a darkhaired or dark-skinned man, from Old Spanish prieto ‘dark’, ‘black’. The adjective derives from the verb apretar ‘to squeeze or compress’, a metathesized form of apetrar, Late Latin appectorare ‘to hold close to the chest’ (from pectus, genitive pectoris, ‘chest’). The use as a color term seems to have derived originally from its application to rain clouds and fog.