9 letters · 14 points in Scrabble
noun abrupt electric discharge from cloud to cloud or from cloud to earth accompanied by the emission of light
noun the flash of light that accompanies an electric discharge in the atmosphere (or something resembling such a flash); can scintillate for a second or more
originFrom light(e)n + -ing. Doublet of lightening.
Etymology from Wiktionary, CC BY-SA 3.0