Region of Gondor containing Minas Ithil (LotR/1115) translated “Land of the Moon” (RC/233). This name is a combination of Ithil “moon” and the plural form of the suffix -ian(d) “land” (SA/sil, PE17/42).
Conceptual Development: This name was already N. Ithilien when it first appeared in Lord of the Rings drafts from the 1940s (TI/318, WR/133).
Ithil (“moon”) + end (commonly used suffix in the names of regions and countries)