INDIGENOUS PEOPLES - Some Working Definitions:

The Draft Declaration on the Rights of Indigenous peoples of the United Nations states that: Indigenous peoples have the collective and individual right to maintain and develop their distinct identities and characteristics, including the right to identify themselves as indigenous and to be recognized as such (article 8) and Indigenous peoples have the collective right to determine their own citizenship in accordance with their customs and traditions. Indigenous citizenship does not impair the right of indigenous individuals to obtain citizenship of the States in which they live (art. 32).

Working definition of the term "Indigenous Peoples" by the United Nations Special Rapporteur for the Study of discrimination against Indigenous Peoples - Mr. Martínez Cobo (applies primarily to the Indigenous Peoples of the Americas, Australasia and the Pacific):
Indigenous communities, peoples and nations are those which, having a historical continuity with pre-invasion and pre-colonial societies that developed on their territories, consider themselves distinct from the other sectors of societies now prevailing in those territories, or parts of them. They form at present non-dominant sectors of society and are determined to preserve, develop and transmit to future generations their ancestral territories, and their ethnic identity as the basis of their continued existence as peoples, in accordance with their own cultural patterns, social institutions and legal systems. In short, Indigenous Peoples are the descendants of a territory overcome by conquest or settlement by aliens.

The definition of Indigenous Peoples as used in the International Labour Organisation Convention No. 169 concerning the working rights of Indigenous and Tribal Peoples (is a bit broader): applies to both tribal peoples whose social, cultural and economic conditions distinguish them from other sections of the national community and whose status is regulated wholly or partially by their own customs or traditions or by special laws or regulations and to peoples who are regarded as indigenous on account of their descent from the populations which inhabit the country at the time of conquest or colonisation.

Description of Indigenous Peoples given by the World Bank (operational directive 4.20, 1991): Indigenous Peoples can be identified in particular geographical areas by the presence in varying degrees of the following characteristics: a) close attachment to ancestral territories and to the natural resources in these areas; b) self-identification and identification by others as members of a distinct cultural group; c) an indigenous language, often different from the national language; d) presence of customary social and political institutions; and e) primarily subsistence-oriented production.