cirith (“pass, cleft”), dû (“nightfall, night, dimness”) + gwath (“shadow”)
Sindarin
cirith dúath
place name. Shadow Cleft
Elements
Word Gloss cirith “cleft, ravine, defile, cleft, ravine, defile, [N.] pass” dúath “night shadow, dark/black shadow, night shadow, dark/black shadow, [N.] night-shade”
Cirith Dúath
noun. pass of shadow
The original name of Cirith Ungol (UT/279-80 note #11), a combination of cirith “cleft” and dúath “night shadow”.