The term Dúnedain (S: "Men [of the] west", singular: Dúnadan) designated the "Edain of the West", those Númenóreans (and their descendants) who emigrated (or later were "exiled") to Middle-earth, although the term came out of use amongst the King's Men and came to denote especially the descendants of the Elendili, the Númenórean Colonists in Arnor and Gondor, or Dúnedain of the North and Dúnedain of the South.
The Noble Families of high blood continued to consider themselves Dúnedain, while they denominated the mixed-blooded common people as "Lesser Dúnedain" or Tarkils (Haeranedain in Rhudaur). The growing racism among the Dúnadain noble families led to many tragedies, such as the separatism of Umbar, the political collapse of Rhudaur and Cardolan, and the Kin-strife in Gondor, and their general waning as a people/culture as their unique gifts were slowly dissipated or withdrawn.
Great People of the West, Men of the Ancient Houses, Men of the West, Men of Westernesse
The Dúnedain enjoyed long life, great power, and wisdom - far superior to the Men of Middle-earth among whom they dwelt and whom they usually ruled. They were from the beginning far fewer in number than those lesser men. They were notably tall, pale-skinned, with dark hair, grey eyes, and proud faces - and often personalities to match.
The description of the Dúnedain of Arnor and Gondor, who seem to be western european and mediterranean in appearance, does not match with their desciption in the Silmarillion and unfinished tales, which describes the Númenóreans as largely of Hadorian descend,these having a largely northern european appearance.
It is possible that the Elendili who mostly hailed from Andustar were an exception and came from a place on Númenor that was settled by more men of Beorian and Halethian origin than the rest of Númenor, which would have been reflected in their descendants.
- "Not all the Dúnedain in Middle-earth were descended from the followers of Elendil. Others had settled there independently before the Downfall, and later allied themselves with the founders of the Kingdoms of the Dúnedain. The ancestors of the Princes of Dol Amroth were among the most prominent of these." -The Encyclopedia of Arda - Dúnedain