Faelivrin was the name that Gwindor bestowed upon Finduilas, the daughter of King Orodreth of Nargothrond, due to his love for her beauty. This name referred to "the gleam of the sun on the pools of Ivrin". Finduilas had loved Gwindor (they had been betrothed before the Nirnaeth Arnoediad) but soon her heart turned to the man that Gwindor had brought into the Elven kingdom, Túrin.
Sindarin
faelivrin
feminine name. *Gleaming of Ivrin
Elements
Word Gloss fael “gleam of the sun; *gleaming” Ivrin
Faelivrin
Faelivrin (name)
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]]].