The name of the Gondorian province that would become Rohan (LotR/678), translated “Green Province” (RC/477) or “(great) green region” (Let/383). The initial element is clearly calen “green” (SA/calen). Tolkien stated that its final element is the suffix -ond “commonly used in the names of regions or countries” (UT/318), but the translation “(great) green region” indicates he may also have considered the augmentative suffix -on². Its middle element is most likely (g)ardh “region”; if so, the ending of this word might be a lenited form of a noun *gardhon meaning “province”.

Conceptual Development: In Lord of the Rings drafts from the 1940s, this region was first named ᴹQ. Elenarda, revised to (mixed language?) Kalenarda or Kalinarda (WR/155-6). Tolkien soon changed the name again to Calenardan >> N. Calenardhon (WR/168), and kept this name thereafter.

Earlier name of Calenardhon in Lord of the Rings drafts from the 1940s (WR/155), perhaps a mix-language combination of N. calen “green” and ᴹQ. arda “realm”. It also appeared as Kalinarda (WR/156), which might be the pure Quenya form of the name as suggested by Roman Rausch (EE/§3.17).

See S. Calenardhon for further discussion.