From Tolkien Gateway

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).[1]

Tolkien noted that the name is Middle English, rare and of vague meaning, taken to mean "Western lands" (in contrast to the East).[2]


In the 13th century chivalric romance King Horn, Westernesse is a kingdom ruled by "King Ailmar" and it is reached by ship by Horn.[1]