Cognomen ใช้ (Chai 
, Usar 
, Usea 
) , throughout the world, is a widespread family name. The family name ใช้ is habitual in Malaysia, where it is a common surname, British Virgin Islands, and Singapore (explore the name in all countries). Not in comparison with a country's population, it is commonest in China, Malaysia, and Indonesia. Much less frequently, ใช้ is the forename as well as the last name.