A group or race of people that share history, traditions and culture, a distinct society.
"A race of men ... an aggregate body of persons, exceeding a single family, who are connected by the ties of a common lineage and perhaps by a common language .... a society of persons occupying a common territory and united under a common government."1
International law often uses the term as if it were synonymous with state as in "United Nations" or 'League of Nations'.
The UN Charter includes a component of self-governance and ignores, within its definition of nation, concepts or units of non-self-governing groups of people.
More recently, the international law has evolved away from the term "nation" as it was commonly known to represent separate countries on thw world map (see old dictionary extract pictured). Conconcurrent with this development, North American Indians bands have enthusiastically adopted the word and commonly refer to themselves as "nations" in order to emphasize their independence; as in the Federation of Saskatchewan Indian Nations (at fsin.com) or Cherokee Nation (cherokee.org). This, even through they are usually completely enveloped within an existing state or country for the purposes of international law, and have no independent standing therein but at the same time relying on this consept to seek, from time to time, international status.
In the result, and notwithstanding its prominence in inter-nation-al law, a contemporary definition of "nation" in international law has proven elusive.
One dictionary (Osmanczyk's "Encycolpedia of the UN and International Agremeents") refers to the word as "an international term having no international definition", a rather circular proposition as the definition itself relies heavily on the term, as in "inter-nation-al law"!
Renan wrote in Qu'est-ce qu'une nation? (1882):
"A nation is a soul, a spiritual principle. Two things which are realy only one go to make up this soul or spiritial principle. One of these things lies in the past, the other in the present. The one is the possession in common of a rich heritage of memories; and the other is actual agreement, desire to live together, and the will to continue to make the most of the joint inheritance.... The existence of a nation is a daily plebiscite, just as that of individuals is a continual affirmation of life."
John Stuart MIlls, in Representative Government (1861), under the heading of "Nationality":
"A portion of mankind may be said to constitute a nationality if they are united amopngst themselves by common sympathies which do not exist between them and any others - which make them cooperate with each other more willingly than with other people, desire to be under the same government, and desire that it should be government by themselves or a portion of themselves, exclusively."
Compare with state which is now, in international law, the preferred term for an independent country which has standing in international law.
References or further reading:
Bernhardt, Rudolf, Encyclopedia of Public International Law (1997).
1. Twiss, Travers, The Law of Nations Considered as Independent Political Communities (London: Oxford University Press, 1861).