The name was given to an isle which is set in the furthest west – mainly for the Elf-friends, comparatively to all other mortal lands. The Elf-friends mostly lived there and became great, powerful mariners after they were rewarded the chance to go west over the sea. After its downfall, the survivors of the Elf-friends were led by Elendil back to the Northwest areas of Middle-earth.
They were the kingdom of men. Tolkien describes them as “fair of face and tall,” in appearance and stature. They lived three times as long as that of the Men of Middle-earth. They were eventually given their name – and the elves called them the Dúnedain.
The native speech was Adúnaic in the later days, abandoning their Elvish-tongue when the kings and lords returned. Adûnaic was spoken with many other words with the “lesser men,” and it became common speech.