Cognomen Kaist (Kaist 
, Каист 
) , in the world, is a rare last name. The cognomen Kaist is habitual in South Korea, where it is a rare surname, Germany, where it is a very rare surname, and Argentina. Measured by absolute frequency, it is the most numerous in South Korea, Germany, and Russia. Much less frequently, Kaist is the forename as well as the last name.