Cognomen Тундер (Tunder 
, Тундер 
) , around the world, is a rare family name. The surname Тундер is habitual in Estonia, where it is quite a rare surname, Romania, where it is a rare surname, and Hungary. In absolute terms, the name is most common in Germany, the United States, and Romania. Very seldom, Тундер is the forename as well as the last name.