Early Primitive Elvish
luhu
root. *time
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.
Middle Primitive Elvish
lu
root. *time
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.
This root and ones like it were the basis for time words throughout Tolkien’s life. The earliest appearance of this root was as ᴱ√LUHU or ᴱ√LU’U (the latter marked by Tolkien with a “?”) in the Qenya Lexicon of the 1910s, unglossed but with derivatives like ᴱQ. lú “24 hours, day” and ᴱQ. lúme “time” (QL/56). It also had derivatives in the contemporaneous Gnomish Lexicon like G. lu “occasion, time” and G. lust “time; tide; weather” (GL/55). It appeared as unglossed ᴹ√LU in The Etymologies of the 1930s with derivatives like ᴹQ. lú “a time, occasion”, ᴹQ. lúme “time”, and their Noldorin cognate N. lhû (Ety/LU).
The Etymologies had a distinct root ᴹ√ULU “pour, flow” (Ety/ULU). It was not explicity connected to ᴹ√LU in this 1930s document, but in notes from around 1959 Tolkien said lūmē “time” was derived from √ULU “flow” (PE17/168), so it is likely that √LU is an inversion of this more basic root.