sîr (“river”), nîn (pl. of nen “water”) + glaur (“gold”); not clear why the second element of Ninglor is not lenited, David Salo states that gh before a nasal could probably revert back to g, before it became zero, TolkLang message 19.31.
noun. gladden (water-gold) river
place name. Gladden River
Sindarin name of the Gladden River (UT/280-1), a combination of sîr “river” and ninglor “golden water-flower”, also seen in Loeg Ningloron “Gladden Fields, (lit.) Pools of the Golden Water-flowers” (S/295; SI/Gladden Fields, Loeg Ningloron).
Conceptual Development: In Lord of the Rings drafts from the 1940s, this river was first named as N. Palathrin “Gladden” (RS/432).
Word Gloss sîr “river, stream” ninglor “golden water-flower, golden water-flower, *yellow iris”