A name applied to various places in the Legendarium: a Southern land of wines in the Lays of Beleriand from the 1920s (LB/11), the land that produced the wines of the Elven-king in the Hobbit, and finally a region near the sea of Rhûn in the Pauline-Barnes map of Middle-earth (LB/26), all of which may be the same place, conceptually. It was also named as a region in Avallon (Tol Eressea) in Silmarillion drafts from the 1930s (LR/334, 338). In his Words, Phrases and Passages from the Lord of the Rings from the late 1950s or early 1960s, Tolkien translated the name as “Young-land country, land of Gwinion” (PE17/54), a combination of dôr “country” and Gwinion “Young-land”.
Sindarin
Dorwinion
'Young-land country'
dorwinion
place name. Young-land country, land of Gwinion
Elements
Word Gloss dôr “land, land, [N.] region where certain people live, [ᴱN.] country; [G.] people of the land” Gwinion “Young-land”
Dorwinion
Dorwinion
The name is Sindarin meaning "Land of Gwinion", whereas Gwinion itself is a name of a country meaning "Young-land"; from dor and gwain plus the geographical ending -iond. Tolkien commented that the Elvish name in such a remote location is a "testimony to the spread of Sindarin". Before the publication of Parma Eldalamberon 17, it had been suggested by Tolkienists that the name may come from an Avarin or Nandorin tongue. Didier Willis speculated that the element -Winion apparently meant "wine", without any probable origin in any known etymology.
topon. 'Young-land country', land of Gwinion. A land prob. far south down the river Running.