Cognomen דאף (Duff 
, דאף 
) , in the world, is a common family name. The surname דאף is habitual in Northern Europe, particularly Aland Islands, where it is quite a common surname, Ireland, and Guernsey (explore the name in all countries). Measured by absolute frequency, this name is the most popular in the United States, the United Kingdom, and Australia. Very seldom, דאף is the forename as well as the last name.