Cognomen Flounder (Flounder 
, Flunder 
) , in the entire world, is a rare surname. The family name Flounder is habitual in the United Kingdom, where it is a very rare surname, Canada, and Australia. Not in comparison with a country's population, it is the most numerous in the United States, the United Kingdom, and Canada. Very seldom, Flounder is the forename as well as the last name.