An Early Noldorin word from the Lays of Beleriand of the 1920s that might mean “lightning” in the name ᴱN. Celeg Aithorn which might mean “Lambent Lightning” (LB/45), but this “translation” of the name might be an unrelated description instead.
Sindarin
aglad
noun. lightning
Elements
Word Gloss agla- “to shine out, flash”
A neologism for “lightning” posted by Elaran in 2018 on the Vinyë Lambengolmor Discord server, a noun formation from ᴺS. agla- “flash”.