Early Noldorin
eithlod
noun. springing, welling forth
eithla-
verb. to spring, well forth
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 word in the Early Noldorin Dictionary of the 1920s given as an infinitive (and noun) eithlod “springing, welling forth”, simply a verb form of ᴱN. aithl “spring” (PE13/158). There was a similar verb G. aithla- “to spring from, bubble up, etc.” in the Gnomish Lexicon of the 1910s (GL/18), altered to aithlo- or aithl- in the Gnomish Lexicon Slips revising that document (PE13/108).
Neo-Sindarin: I think this early verb may be salvaged as ᴺS. eithela-, a verb form of S. eithel “source, spring”.