An unglossed root in the Qenya Lexicon of the 1910s having to do with femininity with derivatives like ᴱQ. qin “woman, female” and ᴱQ. qinde “womanliness, femininity”, as well as various words for “nun” (QL/76). It seems to be related to the Gnomish root ᴱ√GIWI via G(I)WIMI > GWIM > KWIM. In the Gnomish Lexicon beneath various G. gwin- “woman” words Tolkien said: “cp. giwi-; Q qin rare correspondence of q > gw, because it is here from g’w-, not gu̯-” (GL/45). In later writings this root was likely supplanted by √WEN(ED) “woman, maiden, girl”.
Gnomish
guin
adjective. own, held, possessed
guin
adjective. ready, fresh
guin
noun. *woman
gwin
noun. woman, female
arn
noun. son
bo(n)
noun. son
gwein
noun. *woman
nîr Archaic
noun. woman
An adjective appearing as G. guin “own, held, possessed” in the Gnomish Lexicon of the 1910s, above another entry G. guig “a piece of property”, with a brace indicating the two entries had been combined (GL/43). It was likely based on gui the past form of G. gôtha- “possess, have, hold” (GL/42).
Neo-Sindarin: For purposes of Neo-Sindarin, I would update this adjective to ᴺS. garnen “owned, held, possessed” as the passive participle of N. gar- “hold, have” from The Etymologies of the 1930s derived from the root ᴹ√GAR (Ety/GAR). Compare N. garn “property” from the same root.