A native or national of Mongolia, a Mongolian. In the 13th century ad the Mongol empire under Genghis Khan extended across central Asia from Manchuria in the east to European Russia in the west. Under Kublai Khan China was conquered and the Mongol capital moved to Khanbaliq (modern Beijing). The Mongol empire collapsed after a series of defeats culminating in the destruction of the Golden Horde by the Muscovites in 1380.
The term mongol was adopted in the late 19th century to refer to a person suffering from Down's syndrome, owing to the similarity of some of the physical symptoms of the disorder with the normal facial characteristics of East Asian people. In modern English, this use is now unacceptable and considered offensive.