Cognomen 卢西 (Luisi 
, Lucey 
, Luthy 
) , across the world, is a common family name. The cognomen 卢西 is characteristic of Ireland, where it is quite a common surname, Switzerland, and Italy, where it is quite a rare surname. Not in comparison with a country's population, it most frequently occurs in the United States, Italy, and Switzerland. Very seldom, 卢西 is the forename as well as the last name.