Cognomen จันทร์สม (จันทร์สม 
, Jansom 
, Chansom ) , around the world, is quite a rare last name. The last name จันทร์สม is habitual in Thailand, where it is quite a rare surname, and the United Kingdom, where it is an extremely rare surname. Also, จันทร์สม is the forename as well as the last name.