A noun in the Gnomish Lexicon Slips of the 1910s glossed “family, etc.” of unclear derivation, though it may be related to G. eithog “ancestor, †father, sire” (PE13/113).
Gnomish
noss
noun. rain
noss
noun. birthday
nôs
noun. birthday; nature
dana nosteg
birthday
baur
noun. house
eithlos
noun. family
gwaren
noun. family
gwarin(n)
noun. family
The word G. {gwaren >>} gwarin(n) “family” appeared in the Gnomish Lexicon of the 1910s, derived from primitive ᴱ✶ŋuarenđā (GL/44). It was a combination of G. gwa- “together” and G. renni “family” (GL/65), but it is not clear why the e became i in the compound.
Neo-Sindarin: For purposes of Neo-Sindarin I would adapt this word as ᴺS. gwaren as a combination of later prefix gwa- “together” and the Neo-Root ᴺ√RE(N)D “kin”. Furthermore, I would use it specifically for a nuclear family (just the parents and children), as opposed to S. nos(s) which seems to refer to an extended family or clan.
noth
noun. rain
renni
noun. family
A noun in the Gnomish Lexicon of the 1910s glossed “a family”, derived from the early root ᴱ√redh- having to do with kin (GL/65).
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.