star foam; êl (“star”) + wing (“spray, foam”) The meaning of wing is uncertain and could have been taken from Nandorin, but its interpretation is but a guess; later on p.369 this element is said to come from Bëorian tongue; in [Etym. WIG-], the S, Ilk word for “spindrift, flying spray” is given as gwing.
feminine name. Star-spray
Granddaughter of Lúthien, beloved of Q. Eärendil and mother of Elrond and Elros, her name is translated “Star-spray” (S/235, Let/448). This name is a combination of êl “star” and the lenited form of gwing “spray” (SA/wing; PM/365 note #55, 376 note #24).
Conceptual Development: Her name appeared as G. Elwing in the earliest Lost Tales (LT2/241), but in the Gnomish Lexicon from this period her name was translated “Lake Foam”, a variant of the name G. Ailwing (GL/17, 32). In The Etymologies from the 1930s, Tolkien revised the meaning of the initial element of N. Elwing, first deriving it from ᴹ√ƷEL “sky” (Ety/ƷEL), then from ᴹ√EL “star” (Ety/EL). Thereafter, her name remained “Star-spray”, but Tolkien did at times consider that the second element -wing might be borrowed from a non-Sindarin language, either from the language of the Green Elves (PM/349) or from Bëorian (PM/369).
Word Gloss êl “star” gwing “foam, spindrift, foam, spindrift, [N.] flying spray; [G.] wave-crest”