An uninhabited land in Beleriand, translated “Silent Land” (S/121, WJ/194), a combination of dôr “land” and dínen “silent” (SA/dîn).
Conceptual Development: In Silmarillion revisions from the 1950s-60s, Tolkien also used the form Dor Dhínen (WJ/333), reflecting uncertainty over the proper form of the adjective dínen.
(n-)dôr(“land, dwelling-place”), dîn (“silence”) + en (adjective suffix) #The lack of lenition might be explained by Tolkien's dislike for “uncouth” digraph dh.