Early Primitive Elvish
lehe
root. come, be sent, approach
lehe
root. half
lehe
root. *smooth
lefe
root. half
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 implied by entries the Gnomish Lexicon such as ᴱ✶leχa > G. lech/ᴱQ. lea “smooth, slippery”, ᴱ✶leχ-rā > G. lethrin “smooth, slippery, peril(o)us”, and ᴱ✶leχ-sa > G. lais “green sward, glade” (GL/53). There are no signs of this root in Tolkien’s later writing.