The speed at which light travels in a vacuum; the constancy and universality of the speed of light is recognized by defining it to be exactly 299,792,458 meters per second. Synonyms:c, speed of light.
... me, thou Star, whose wings of light Speed thee in thy fiery flight, In what cavern of the night ... — The Complete Poetical Works of Percy Bysshe Shelley Volume I • Percy Bysshe Shelley Read full book for free!