Q. rissë n. “?cleft, ravine” (Category: Ravine, Pass)
An unglossed Quenya noun from notes Words, Phrases and Passages from the Lord of the Rings, apparently derived from primitive ✶rinse where the [ns] became [ss] in Ancient Quenya (PE17/87). It was related to the final element of S. Imladris “Rivendell, (lit.) Deep Dale of the Cleft” and so perhaps means “*cleft, ravine”.
Reference ✧ PE17/87 ✧ risse
|✶rinse > risse||[rinse] > [risse]||✧ PE17/87|