Mayang is a term used by the Manipuri in Manipur to refer to non-Manipuri Indians, especially the speakers of Hindustani language and Bengali people But historically the term has been used to denote the Bishnupriya Manipuris and Bengalis, who are considered by Meiteis to be outsiders in Manipur. The term was later casually used to denote 'foreigner' during the militancy in Manipur, which effectively translated to Indians from outside the state. Indians in general and Bengalis in particular became the targets of attacks. According to journalist Kishalay Bhattacharjee, the term is synonymous to Dkhar in Meghalaya.
Usage.
The term is used for who are not from Manipuri. It is a term which means foreigner in Manipuri dialect.
Kwak Mayang.
The Corvus splendens or Indian crow is known as Mayang Kwak in Meitei language. The Meiteis maintain that Indian crow originally was not native to Manipur. As it arrived from the west, it is known as Mayang Kwak, literally meaning 'foreign crow' or 'western crow'. Australian dancer Louise Lightfoot has recorded in her memoir a popular game among the Meitei children called 'Kwak Mayang', literally meaning 'foreign crow'. 
Mayang Hallo.
Militants raised the violent war cry of 'Mayang Hallo!', literally meaning 'Foreigners go back!'. With the influx of People from Mainland India in the small state,it becomes a threat to the local indigenous population 
References.
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