A sobriquet of Finduilas translated “gleam of the sun on the pools of Ivrin” (S/210). This name is a combination of fael (“gleaming”?) and the name Ivrin.
Conceptual Development: In the earliest Lost Tales, this name first appeared as G. Failivrin and was this Elf-maiden’s only name (LT2/82, 124). In the Lays of Beleriand from the 1920s, this name was given essentially the same translation as its later form: “glimmering sheen on the glassy pools of Ivrin’s lake” (LB/76); at this stage her given name G. Finduilas was also introduced. The name remained N. Failivrin in Silmarillion drafts from the 1930s (SM/127), but was changed to S. Faelivrin in the published version of The Silmarillion, along with other [[n|revisions of [ai] to [ae]]].
An element in the name Faelivrin described as the “gleam of the sun on the pools of Ivrin” (S/210), hence probably meaning something like “gleam of the sun” or “✱gleaming”. It may be derived from the root ᴹ√PHAY in its 1930s sense “radiate, send out rays of light” (Ety/PHAY), though in later writings √PHAY meant “spirit” (PM/352).