An orc-fortress in Mordor (LotR/928), translated “Dark Press or Oppression” (RC/610). This name is a compound of dûr “dark” and thang “oppression” (SA/dûr, thang).
Conceptual Development: This name was already N. Durthang when it first appeared in Lord of the Rings drafts from the 1940s (SD/33).
dûr (“dark”) + thang (“compulsion, oppression”)