Cognomen Erbai (Erbai 
, Ербай 
) , in the entire world, is a very rare last name. The family name Erbai is characteristic of Georgia, where it is a rare surname, Kazakhstan, where it is a very rare surname, and Palestinian Territory. In absolute terms, it is the most numerous in Kazakhstan, Georgia, and Ukraine. Much more prevalently, Erbai is the forename as well as the last name.