Cognomen 加伊 (Gaj 
, 加伊 
) , in all the world, is quite a common last name. The last name 加伊 is characteristic of Suriname, where it is quite a rare surname, Poland, and Slovakia. Not in comparison with a country's population, this name is the most popular in Poland, India, and the United States. More prevalently, 加伊 is the forename as well as the last name.