Name of the halls of Ulmo in the earliest Lost Tales (LT1/68, 85), the etymology of its second element is unclear.
Early Quenya
ulma
noun. flagon
ulmonan
place name. Ulmo’s Halls
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 appearing as ᴱQ. ulma “flagon” in the Qenya Lexicon of the 1910s derived from ᴱ✶ḷma (QL/97). Tolkien said it was not related to the early root ᴱ√ULU “pour” because Gnomish derivatives of that root showed gul- (indicating a true root form ✱ᴱ√GULU), whereas the Gnomish cognate of this word was G. ulm (GL/74).
Neo-Quenya: Tolkien soon changed his mind and decided the root for “pour” was in fact ᴱ√ULU. I would therefore retain ᴺQ. ulma for purposes of Neo-Quenya, but would assume it was derived from ✱ul-mā “a thing for pouring”. As such, I would assume its use also included pitchers with handles as well as flagons; this is how Helge Fauskanger used ulma in his NQNT (NQNT).