A suffix meaning “-land” or “country” appearing often in the names of regions and countries along with its plural variant -ien(d) “-lands”, mentioned in a number of places in Tolkien’s later writings (Let/383; UT/318). In notes from the late 1950s Tolkien derived it from primitive ✶yandē “a wide region or country” from the root √YAN “wide”, which replaced another root √YON of similar meaning (PE17/42-43). In notes having to do with “large & small” words, probably from the late 1960s, Tolkien connected it instead to an apparent adjective S. iand “wide”, still derived from √YAN (PE17/115).
Conceptual Development: This suffix seems to have first appeared in ᴱN. Broseliand in the Lays of Beleriand of the 1920s, precursor to the name S. Beleriand and almost certainly inspired by the legendary medieval French forest Brocéliande. Tolkien used this suffix widely in names starting with Lord of the Rings drafts, but it seems he did not develop a clear etymology for the suffix until quite late. Tolkien himself mentioned the connection between this suffix and the French name Brocéliande in a 1967 letter (Let/383). It is thus an interesting case study in how Tolkien would gradually integrate elements inspired by real-world languages into his Elvish corpus.