Quenya 

celussë

noun. freshet, water falling out swiftly from a rocky spring

Quenya equivalent of the river name S. Celos, glossed “freshet, water falling out swiftly from a rocky spring” and derived from a combination of ✶kelu- “flow (swiftly)” and the abstract noun suffix -ssë (UTI/Celos). A shorter primitive form {kelut >>} ✶kelus “brook” appeared in the Common Eldarin: Verb Structure (EVS2) from the early 1950s (PE21/71).