The wine of Dor-Winion occurs in the Lay of the children of Húrin and a place located either in the "burning South" in the first version, or probably east of the Blue Mountains in the second. Then we have Dorwinion as a meadow-land in Tol Eressëa at the end of the Quenta Silmarillion. It reappears in The Hobbit, and was finally placed North-West of the Sea of Rhûn in the decorated map by Pauline Baynes (see HL/115-117 for discussion). The meaning of this name is unknown and has been largely discussed. What do we have indeed in this "Winion", or rather gwinion since the initial w- must come from lenition? According to Christopher Tolkien, the Lay was begun c. 1918 and was composed during his father's stay at Leeds, a date meaning that the word can be Gnomish, possibly Early Noldorin, or in an indigenous language of Beleriand. In Gnomish and later in Doriathrin and Ilkorin, there is a genitive plural ending -ion which may very well be contained in this word. Then we would segment gwin-ion "of gwin". The context calls for "wine", "vine" or something similar. It can hardly be a coincidence that gwin is precisely the Welsh word for "wine", a loan from the Latin vinum, as the English "wine" itself
Sindarin
gwîn
noun. youth
gwîn
noun. wine, vine
gwîn
noun. youth
gwîn
pronoun. our (inclusive)
gwain
new
(gwin-), lenited ’wain, pl. gwîn. Isolated from the month-name Narwain, ”new sun” (where #gwain appears in lenited form). The form gwîn ”young” listed in VT46:22 would have to be taken as a pl. form, if it is to be the cognate of Quenya vinya.
n. youth. Q. víne. >> gwein