Quenya 

sírima

liquid, flowing

sírima adj. "liquid, flowing" (LT1:265)

Sindarin 

ylin

noun/adjective. liquid

Sindarin Group: Eldamo - neologism/adaptations. Published by

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!

Early Quenya

sírima

adjective. liquid, flowing

Early Quenya [LT1A/Sirion; QL/084] Group: Eldamo. Published by

Gnomish

glib

adjective. liquid

An adjective in the Gnomish Lexicon of the 1910s glossed {“dripping wet” >>} “liquid” (GL/39), probably derivatives of the early root ᴱ√LIQI which had derivatives like ᴱQ. liqin(a) “wet” (QL/54).

ulin

noun/adjective. liquid

A word in the Gnomish Lexicon of the 1910s appearing as G. ulin “liquid” (GL/74), clearly a derivative of the early root ᴱ√ULU “pour, flow fast” (QL/97).

Neo-Sindarin: If adapted to (Neo) Sindarin, this word would be ᴺS. ylin with i-affection, probably originally an adjective formation: ✱ulin(a).