Family name Кайди (Kajdi 
, Кайди 
) , throughout the world, is a rare cognomen. The surname Кайди is characteristic of Hungary, where it is quite a rare surname, Austria, where it is a rare surname, and Croatia. In absolute terms, this name is the most popular in Hungary, the United States, and Germany. Very seldom, Кайди is the forename as well as the last name.