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
There are more words but they are from Tolkien's earlier conceptional periods. Tolkien likely changed these words as he evolved the aesthetics and completeness of the languages. You may even find languages that Tolkien later rejected. Do not mix words from different time periods unless you are familiar with the phonetic developments.
Below: Tolkien's Late Period (1950–1973). These are from Tolkien's late conceptual period — his most settled forms of the languages. Prefer these over the earlier ones above when composing new text.
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.