A noun appearing as G. omlos “(horse) chestnut tree” in the Gnomish Lexicon of the 1910s, an elaboration of G. omla “a horse chestnut” (GL/62).

Neo-Sindarin: Its etymology was obscure even in the 1910s, but since there are no later alternatives I would retain ᴺS. omlos “chestnut tree” for purposes of Neo-Sindarin. Its initial element would have to be based on something like omb- for the m to have survived; compare to S. imlad < ✶imbi-lătă (PE17/87). Since I don’t see a way to salvage G. omla, I would use ᴺS. omlos for a “chestnut” as well.