Adan, Edain

'Father-of-Man' (Sind. from Q. Atan, Atani) The Elves' name, given in friendship, for those among men who came across the Blue Mountains into Beleriand during the First Age, and fought alongside the Elves as allies in their long wars against Morgoth the Enemy.
Like the Elves, the Edain were of Three Kinds, or Houses, led during the wars by Hurin, Turin, and Hador the Goldenhaired. Beren and his father Barahir were of the First House; the Second House (of Turin) had much to do with Dwarves; while the Third House (of Hador) was closest in friendship with the Eldar and became most renowned in battle.
At the ending of the First Age, in return for their sacrifices in the wars, the Edain were granted land 'West-over-Sea'- the Isle of Elenna, most waterly of mortal lands. Using Earendil's Star as their beacon, the greater part of them then set out for their futire home. They named their new realm Numenor.
The Elves then called this people Dun-edain, 'Men-of-the-West'. And the Numenoreans began to grow more kingly and proud, and more like the Eldar themselves, with whom they lived in friendship for the greater part of the Second Age; for they had also been rewarded with longer life than other men, though not with that immortality they always desired. Yet Numenor withered and and fell at last, and few survived: only the Faithful, led back to Middle-earth by Elendil the Tall. Like the Elves, they were a dwindling people.



From The Tolkien Companion by J.E.A. Tyler