The inland sea in the middle of Mordor. Its final element is clearly nen “water, lake” (SA/nen). The meaning of its initial element is less clear, though it may simply incorporate the name of the region containing the sea: Nurn.

Possible Etymology: In The Lord of the Rings, this sea was described as “the dark sad waters” (LotR/923) and its name was glossed “Sad Water” in Tolkien’s “Unfinished Index” of The Lord of the Rings (RC/457). However, there is no attested Sindarin word nûr with a meaning similar to “sad”.

In Words, Phrases and Passages from the Lord of the Rings from the late 1950s or early 1960s, Tolkien translated the name as “Death/dead water” (PE17/87), with its first element derived from √ÑGUR “death”. Elsewhere the Sindarin word for “death” is guru, so maybe Tolkien intended the first element to be from its Quenya cognate [ᴹQ.] nuru. Perhaps the poisoned waters of Mordor made life within Núrnen difficult, like the Dead Sea of Earth.

Hammond and Scull suggested the two concepts could be related, with “sad” being used in the sense “bitter” or “unpalatable”, referring to its poisoned waters (RC/457).

Conceptual Development: This name first appeared on the first draft map of The Lord of the Rings as N. Nurnen with a short u (TI/309). It later appeared with a long u, as N. Nûrnen (WR/127) and N/S. Núrnen (SD/56).