A rough Westron translation of the name Rhovanion, and was thought to refer to the large area of the lands east of Arnor and north of Gondor not claimed by either kingdom.

The area was bounded by the Misty Mountains to the west, the Grey Mountains to the north, the Sea of Rhun to the east, and the boundaries of Mordor and Gondor at the Ash Mountains and White Mountains to the south. The River Anduin flowed through Wilderland between the Misty Mountains and the forest of Mirkwood.
Encyclopedia entry originally written by PotbellyHairyfoot