A well-established word for “beach” or “shore”, derived from the root √PHAL “foam, splash” (PE17/62, 73).
Conceptual Development: In the Gnomish Lexicon of the 1910s this word appeared as G. falos “sea-marge, surf, coast, line; margin, fringe, edge” (GL/33), but it was G. falas “beach” in the contemporaneous Name-list to The Fall of Gondolin (PE15/24) as well as in names from this period such as G. Falas-a-’Wilb “Beach of Peace” and G. Falathron = “Ossë”. It appeared as N. falas “beach, shore” in The Etymologies of the 1930s derived from the extended form ᴹ√PHÁLAS of the root ᴹ√PHAL “foam” (Ety/PHAL). Similar derivations appeared in Tolkien’s later writings well (PE17/62, 73).
Region on the coast of Beleriand (S/58). This name is simply the word falas “shore, coast” used as a name (SA/falas). This name sometimes appears with the definite article: i Falas “The Coast” (VT42/15, Ety/PHAL). It sometimes was translated “Western Shore/Coast” (LR/128, Ety/PHAL), but the word for “west” did not appear in its Sindarin name.
Conceptual Development: This name first appeared as N. Falas in Silmarillion drafts from the 1930s (SM/121, LR/128), and in The Etymologies already had the derivation given above (Ety/PHAL).