Qenya
isil
noun. Moon, (lit.) Sheen
en kárielto eldain isil, hildin úr-anar; toi írimar
for Elves they made the Moon, but for Men the red Sun; which are beautiful
nú
proper name. Moon
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 name for the moon in linguistic notes from 1930s (PE21/38, 41), perhaps a derivative of the root ᴹ√NDŪ “go down”, though this root usually applied to the Sun. Its dual form Nunt referred to both the sun and moon (PE21/38).