Light·en v. i. [imp. & p. p. Lightened p. pr. & vb. n. Lightening.]
1. To burst forth or dart, as lightning; to shine with, or like, lightning; to display a flash or flashes of lightning; to flash.
This dreadful night,
That thunders, lightens, opens graves, and roars
As doth the lion. --Shak.
2. To grow lighter; to become less dark or lowering; to brighten; to clear, as the sky.