Gloss
From Tolkien Gateway
gloss is a Sindarin word meaning snow-white or dazzling white.
Etymology
Probably OS *glosse < Root G-LOS
References
- J.R.R. Tolkien, Donald Swann, The Road Goes Ever On, p.70
- J.R.R. Tolkien, Christopher Tolkien (ed.), The Lost Road and Other Writings, "The Etymologies", p. 359