Cognomen Muyn (Муин 
, Muyn 
) , in all the world, is a very rare surname. The family name Muyn is habitual in Kyrgyzstan, where it is a very rare surname, Kazakhstan, and Russia, where it is an extremely rare surname. In absolute terms, it is the most numerous in China, Russia, and Kazakhstan. More frequently, Muyn is the forename as well as the last name.