Literary or poetic term for a lightning flash; in everyday speech 稲妻 (いなずま) or 雷光 (らいこう) are more common.
A flash of lightning tore across the night sky.
fulgurite
Composed of 閃 (flash, flicker) and 電 (electricity, lightning). The exact historical derivation is uncertain; the spelling is conventionally associated with the meaning 'flash of lightning'.