What is the name of the large island in the D&D world of Nerath? I guess it could be a continent also.
The island is called Kelarnil based on the following excerpt from The Seven Kings of Karkoth
Karkothi legions menace the fair realms of Vailin, the valiant Seldurian tribes that remain loyal to the old ideal of Nerath, and the great island of Kelarnil from their foothold in the Dread Marches.
Dread Marches is the north east territory on the main island which indeed belongs to Karkoth.