>
Cognomen Koos (Koos , 库斯 , Кос ) , globally, is a common surname. The last name Koos is habitual in Hungary, where it is quite a common surname, Ukraine, where it is quite a rare surname, and Luxembourg. Measured by absolute frequency, the name is most common in Hungary, Ukraine, and Germany. Likewise, Koos is the forename as well as the last name.