Westernesse was a name in the Common Speech for the Isle of Númenor.
The ending -ess (also in Elvenesse) was used in romance literature for fictional lands that had partly francized names (as in Lyonesse in Arthurian legends).
In the 13 century chivalric romance King Horn, Westernesse is a kingdom ruled by "King Ailmar" and it is reached by ship by Horn.
- ↑ 1.0 1.1 J.R.R. Tolkien, "Nomenclature of The Lord of the Rings" in Wayne G. Hammond and Christina Scull (eds), The Lord of the Rings: A Reader's Companion, pp. 778-9