S. dúath n. “night shadow, dark/black shadow” (Category: Shade, Shadow)
A word meaning “night shadow” (PE17/152) or “dark/black shadow” (PE17/87), a combination of dû “night” and the soft-mutated form ’wath of gwath “shadow” (SA/dú, gwath), usually written dúath but sometimes dúwath or duwath. Most notably it appeared in the name Ephel Dúath “Mountains of Shadow; (lit.) Fence of Shadow” (LotR/636; RC/457). In one place Tolkien said it was used metaphorically for darkness as an ethereal substances, the opposite of glae(gal) which was light as a substance (NM/283).
Conceptual Development: N. Dú(w)ath “night-shade” appeared in The Etymologies of the 1930s, already with the etymology given above (Ety/DOƷ).
References ✧ NM/283; PE17/87, 152; SA/dú, gwath
|dû||“night, dimness; dim, dark”||✧ PE17/87; PE17/152; SA/dú (dú)|
|gwath||“shadow, dim light”||✧ SA/gwath (wath)|