Another name for Nienna in the earliest Lost Tales (LT1/66), derived from the root ᴱ√NURU having to do with growling (QL/68).
Early Quenya
nienna
feminine name. Nienna
fui
feminine name. Death-goddess, Nienna
núri
feminine name. Fui
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
Sobriquet for the female Vala ᴱQ. Fui, at this stage the wife of Mandos (LT1/66). Her name appeared as Nyenna in the Qenya Lexicon, a derivative of either ᴱ√NYE(NE) “bleat” or ᴱ√NYEHE “weep” (QL/68).