(idiomatic, transitive) To motivate or encourage (someone) to start sooner or move faster.

Faster than the speed of light in a vacuum, the theoretical speed limit for travel within the universe.

(Australia) An unexplained light reportedly appearing in the sky in remote parts of Australia, especially northwest Queensland, possibly caused by reflections of distant light in the dry air conditions.

circularly polarized light

(physics) polarized light in which the electric and magnetic fields vibrate in same phase

(physics) any optical method used to measure the extent of the scattering of light by suspended particles or by macromolecules

(physics) A rectifying semiconductor device which converts electrical energy into electromagnetic radiation of a wavelength in or near the visible spectrum of light.

Any joke of the form "How many X does it take to change a light bulb?" followed by a witty riposte, where X is some usually stereotypical class of people.

An area of a town where prostitution is concentrated.

(simile, colloquial) Asleep or unconscious, particularly if this has occurred suddenly and the sleep is deep.