Third great battle of the Wars of Beleriand, translated “Glorious Battle” (S/115), a combination of dagor “battle” and aglareb “glorious” (SA/aglar).
Conceptual Development: In Silmarillion drafts from the 1930s, this battle was already called N. Dagor Aglareb when it was first named (SM/329).
dagor (“battle”), aglar (“glory”) + eb (adjective suffix)