A noun for “rain” in the Gnomish Lexicon of the 1910s derived from primitive ᴱ✶ukko (GL/74), probably based on the early root ᴱ√UQU “wet” which had derivatives like ᴱQ. ukku “rainbow” (QL/98).
Gnomish
nôs
noun. birthday; nature
noss
noun. rain
nôs mora
good by nature
nosi mora
good by nature
noss
noun. birthday
dana nosteg
birthday
noth
noun. rain
uch
noun. rain
A word appearing as G. {noss >>} nôs “birthday” in the Gnomish Lexicon of the 1910s (GL/61), clearly based on the early root ᴱ√NŌ “become, be born” (QL/66). In the contemporaneous Gnomish Grammar it appeared with the gloss “nature” in phrases like nôs mora “good by nature” (GG/10).
Neo-Sindarin: The usual Neo-Sindarin word for “birthday” is ᴺS. oronnad, a combination of aur “day” and [ᴺS.] onnad “birth”. The word has been floating around for long enough that I have no idea where it originated, but I first learned of it from Fiona Jallings’s Sindarin word lists.