One of the beacon hills of Gondor (LotR/747), translated “Green Space” and a combination of calen “green” and the lenited form -had of sad “place” (VT42/19), though Tolkien said its final element could also be sâdh “sward, turf” (VT42/20).
Conceptual Development: In Lord of the Rings drafts from the 1940s, this hill was named N. Calenhad when it first appeared (WR/233).
calen (“green”) + sad (“limited area naturally or artificially defined, a place, spot”)