A stream in Gondor flowing into the river Sirith (LotR/875). It is a cognate of Q. celussë “freshnet”, derived from a combination of ✶kelu- “flow out swiftly” and the primitive abstract-noun suffix ✶-ssē/-ssā (UTI/Celos). The Sindarin name is most likely derived from primitive ✶kelussā, because primitive short [i], [u] became [e], [o] preceding final [a], with the final [a] lost later.

Conceptual Development: In Lord of the Rings drafts from the 1940s, this name first appeared in a list of rivers in Gondor as N. Kelos (TI/312).