In the west it was said this way
And until it fall it alone held sway
In the days of power it came to a head
taken from the early men some said.
Believed to be "Adunaic". "Numenor" was tried and is wrong. Some think "Numenorian" may work.
Adûnaic ("Language of the West") was the Númenórean language, spoken by the Men of Númenor during the Second Age.
Tolkien Gateway: Adûnaic