Early Quenya
nénu
noun. yellow water lily
nenyu
noun. yellow water-lily
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.
A word for a “yellow water lily” in the Qenya Lexicon and Poetic and Mythological Words of Eldarissa of the 1910s derived from the early root ᴱ√NENE “flow” that was the basis for river and water words (QL/65; PME/65). In the Qenya Lexicon it had a variant form nenyu.