J.R.R. Tolkien’s invented language for the Men of Númenor was Adûnaic.
Adûnaic, also spelled Adunaic in simplified forms, was the language of Númenor’s inhabitants in Tolkien’s mythology. Tolkien developed material for it especially in writings associated with the unfinished linguistic and narrative work later published in Sauron Defeated.
The language belongs to the Mannish linguistic history of Middle-earth rather than to the Elvish family. Sindarin and Quenya are Elvish languages, while Khuzdul is associated with the Dwarves. Westron is the Common Speech used widely in the later stories.
Adûnaic is consequently easy to mix up with Tolkien’s better-known constructed languages. Its importance comes from Númenor’s history and from Tolkien’s sustained interest in showing how languages change as peoples migrate, interact, and decline.