A street in Minas Tirith translated “Lampwrights’ Street” (LotR/768), a combination of rath “street” and the plural of calardan “lampwright” (RC/523, PE17/96).
Conceptual Development: In Lord of the Rings drafts from the 1940s, this name first appeared as (singular) N. Rath a Chalardain >> (plural) Rath a Chelerdain (WR/388). This form seems to included the genitive preposition N. an “of”, elided and causing nasal mutation of the following noun, as suggested by Roman Rausch (EE/3.25).
rath (“street”), celerdain (pl. of calardan “lampwrights” < calar (“lamp”) + tan (“maker, smith”)