Cognomen Dounai (Dounai 
, Дунай 
, Дунаи ) , in the world, is quite a rare family name. The last name Dounai is characteristic of Belarus, where it is quite a rare surname, Ukraine, and Kyrgyzstan, where it is a rare surname. Measured by absolute frequency, the name is most common in Eastern Europe, particularly Ukraine, Belarus, and Russia. Much less frequently, Dounai is the forename as well as the last name.