J.R.R. Tolkien’s invented language of the Númenóreans was called Adûnaic.
Adûnaic, also spelled Adunaic in some contexts, was the language spoken in Númenor by the descendants of Men who lived on the island kingdom. Tolkien developed material for it especially in connection with the unfinished writings later published in The History of Middle-earth.
It is different from Quenya and Sindarin, which are Elvish languages, and from Khuzdul, the language associated with the Dwarves. Tolkien’s languages were linked to fictional histories, migrations, and relationships between peoples rather than being isolated word lists.
Adûnaic is less fully developed in surviving material than Tolkien’s best-known Elvish languages. That limited evidence is one reason it is usually discussed through Tolkien’s wider Númenórean and Second Age writings.