A source of light is any object that emits light, which can be natural or artificial. A LAMP, with four letters, is an artificial source of light, usually powered by electricity. The SUN, with three letters, is a natural source of light, and is the main source of energy for life on Earth. GLIM, with four letters, is an old-fashioned term for a light source, such as a candle or oil LAMP. Finally, a LANTERN, with seven letters, is a portable source of light, usually powered by a flame or battery.