A noun for “rivulet” in the Declension of Nouns of the early 1930s (PE21/33, 35), clearly a derivative of ᴹ√KEL(U) “flow”.
Qenya
siril
noun. rivulet
kelut
noun. rivulet
sirya-
verb. to flow [smoothly]
Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!
A noun for “rivulet” in The Etymologies of the 1930s derived from the root ᴹ√SIR “flow” (Ety/SIR).