Mleccha (from Vedic Sanskrit म्लेच्छ mleccha, ම්ලේච්ච meaning "non-Vedic", "barbarian"), also spelled Mlechchha or Maleccha, is a name, which referred to people of foreign extraction in ancient India. Mleccha was used by the ancient Indians much as the ancient Greeks used barbaros, originally to indicate the uncouth and incomprehensible speech of foreigners and then extended to their unfamiliar behaviour, and also used as a derogatory term in the sense of "impure and/or "inferior" people.
In ancient India, this term was also applied by the ancient Indian kingdoms to foreigners especially Persians. The word Mleccha was commonly used for 'outer barbarians of whatever race or colour'.
The Indians referred to all alien cultures that were less civilized in ancient times as 'Mlechcha' or Barbarians. Among the tribes termed Mlechcha were Sakas, Huns, Yavanas, Kambojas, Pahlavas, Bahlikas and Rishikas. The Amarakosha described the Kiratas and Pulindas as the Mleccha-jatis. Indo-Greeks, Scythians, and Kushanas were also mlecchas.
The Vayu, Matsya and Brahmanda Puranas state that the seven Himalayan rivers pass through mleccha countries. The Brahmanas place mlecchas outside the varna system. Southworth suggests that the name comes from miḻi- "speak, one's speech", might have been derived from the etymology of the word Tamiḻ. The term Mencha, probably a tadbhava, was also used by the medieval Marathi saint Samarth Ramdas, a Hindu sant, author and Advaita Vedanta philosopher, to refer to the invading Mughals, who were both Muslims and ruled by Mongols.