Gnomish
celu-
verb. to trickle
celu
noun. rill, stream, runlet
celwa-
noun. to trickle
aithl
noun. spring
aithyl
noun. spring
celwin
noun. rill, stream, runlet
duif
noun. stream
hairen
feminine name. Spring
tuil
noun. spring
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 verb appearing as celu- or [cel]wa- “trickle” in the Gnomish Lexicon of the 1910s (GL/25), clearly cognate to ᴱQ. kelu- “to flow” (QL/46).