Cognomen 사이 (Sy 
, Cy 
, Kanakubo 
) , in all the world, is a widespread family name. The cognomen 사이 is characteristic of Syria, where it is a prevalent surname, Senegal, where it is a widespread surname, and Mauritania, where it is a common surname (explore the name in all countries). Not in comparison with a country's population, this name is the most popular in Syria, Senegal, and Philippines. Much less frequently, 사이 is the forename as well as the last name.