A collective-noun meaning “all the stars of the heavens”, as opposed to gimli which was used for an individual star (SD/427). The element gimil appears in many names, including several later names in The Lord of the Rings and The Silmarillion. Carl Hostetter and Patrick Wynne suggested (AAD/15) that it may be related to the Elvish root √(Ñ)GIL “shine (white)”.
Andreas Moehn suggested (EotAL/KH-B-L) that if the later name Gimilzôr means “Silver-fire”, its initial element gimil could instead mean “silver”, perhaps as a cognate of Dwarvish kibil. If so, this alternate meaning could either be a homonym of gimil “stars”, or a new meaning for gimil in Tolkien’s later works.