A noun for a cut through earth or rock: a cleft, ravine, defile or pass. It is an abstract noun formation from the root √KIR “cut, cleave”, and thus might have other non-geographic applications such as “a cutting”, but the word criss “cut, slash” is probably better for such purposes.
Conceptual Development: This word first appeared in some revisions to Silmarillion drafts in the early 1930s, as {N. Cris-Ilfing >>} N. Kirith Helvin and {N. Cristhorn >>} N. Kirith-thoronath (SM/146). Neither of these names became established at this stage, but the word Kirith reappeared in Lord of the Rings drafts in 1940s, in names like N. Kirith Ungol “Spider Glen” (TI/330) and N. Kirith Gorgor “Dreadful Pass” (WR/122), after which Tolkien used this word widely. In the Nomenclature of the Lord of the Rings from 1967, Tolkien explained cirith as meaning: “a cleft, a narrow passage cut through earth or rock (like a railway cutting)” (RC/767).
n.