This appears to be an adjectival form of glaur “gold (colour or light)” seen only as a element in names like Galadlóriel “Golden Rain” (MR/155; RS/187) [not an exact translation] and Rathlóriel “Golden-bed” (S/235).
Conceptual Development: In The Etymologies of the 1930s these names had a short o under the root ᴹ√(G)LAWAR, indicating a Noldorin form of N. gloriel (Ety/LÁWAR). The Gnomish Lexicon of the 1910s had G. glôriol “golden, like gold” based on G. glôr “gold” (GL/40).
An adjectival form of glaur “gold (colour or light)” seen only as a element in the name Glórindol “Goldenhead” (S/147; WJ/225, 234).
Conceptual Development: The Gnomish Lexicon of the 1910s had G. glôrin “golden, of gold” based on G. glôr “gold” (GL/40).