Throughout the world, ต้นน้ำ (Tonnam 
, ต้นน้ำ, Tontam 
) is a very rare unisex forename. The first name ต้นน้ำ is characteristic of South-eastern Asia, particularly Thailand, where it is a very rare epicene name. Also, ต้นน้ำ is the last name as well as the forename.