A noun meaning “west(ward)” (SD/435, PE17/18). Tolkien stated that was “a loan word from Eldarin speech in the language of the Folk of Hador, from which Númenórean was later derived” (PE17/18). Probably it is derived from S. dûn “west”, as suggested by several authors (AAD/9, EotAL/NDU). Tolkien stated that it was an adjective and its proper noun form was adûni (SD/435), but adûn was used as a noun in phrases such as Bârîm an-adûn “Lords of the West” (SD/247).
adûnnoun. west, westward