What is Light?

Light definition and meaning on Dictionary terms:
something that makes things visible or affords illumination: All colors depend on light.
Physics. Also called luminous energy, radiant energy.electromagnetic radiation to which the organs of sight react, ranging in wavelength from about 400 to 700 nm and propagated at a speed of 186,282 mi./sec (299,972 km/sec), considered variously as a wave, corpuscular, or quantum phenomenon.a similar form of radiant energy that does not affect the retina, as ultraviolet or infrared rays.

the sensation produced by stimulation of the organs of sight.
an illuminating agent or source, as the sun, a lamp, or a beacon.
the radiance or illumination from a particular source: the light of a candle.
the illumination from the sun; daylight: We awoke at the first light.
daybreak or dawn: when light appeared in the east.
daytime: Summer has more hours of light.
a particular light or illumination in which an object seen takes on a certain appearance: viewing the portrait in dim light.
a device for or means of igniting, as a spark, flame, or match: Could you give me a light?
a traffic light: Don’t cross till the light changes.
the aspect in which a thing appears or is regarded: Try to look at the situation in a more cheerful light.
the state of being visible, exposed to view, or revealed to public notice or knowledge; limelight: Stardom has placed her in the light.
a person who is an outstanding leader, celebrity, or example; luminary: He became one of the leading lights of Restoration drama.
Art. the effect of light falling on an object or scene as represented in a of the brightest parts of a picture.

a gleam or sparkle, as in the eyes.
a measure or supply of light; illumination: The wall cuts off our light.
spiritual illumination or awareness; enlightenment.
Architecture. Also called compartment of a window or window sash.a window, especially a small one.

mental insight; understanding.
lights, the information, ideas, or mental capacities possessed: to act according to one’s lights.
a lighthouse.
Archaic. the eyesight.

adjective, light