Cognomen ขันน้ำ (Khannam 
, ขันน้ำ) , in all the world, is quite a rare surname. The cognomen ขันน้ำ is habitual in India, where it is a rare surname, Thailand, where it is an extremely rare surname, and the United Kingdom. Very seldom, ขันน้ำ is the forename as well as the last name.