Family name Clausum (Close 
, Kloss 
, Clós ) , in the world, is a common last name. The cognomen Clausum is habitual in Jersey, where it is quite a common surname, Belgium, and Australia, where it is quite a rare surname. Measured by absolute frequency, this name is the most popular in the United States, Germany, and the United Kingdom. Much less frequently, Clausum is the forename as well as the last name.