To burst forth or dart, as lightning; to shine with, or like, lightning; to display a flash or flashes of lightning; to flash.(verb)
source: webster1913
To make light or clear; to light; to illuminate; as, to lighten an apartment with lamps or gas; to lighten the streets.(verb)
source: webster1913
To make lighter, or less heavy; to reduce in weight; to relieve of part of a load or burden; as, to lighten a ship by unloading; to lighten a load or burden.(verb)