Middle Primitive Elvish
nūrā
adjective. deep
nur
root. deep
tubnā
adjective. deep
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 root mentioned in The Etymologies as an extension of ᴹ√NU with the gloss “deep” and derivatives ᴹQ. núra and N. nûr of the same meaning (Ety/NU). Possibly related is the later word Q. nurtalë “hiding” as in Q. Nurtalë Valinóreva “Hiding of Valinor” (S/102).