A lot vs. Alot: 9 Grammatical Pitfalls
1968, initialism from light-emitting diode.
Short for light-emitting diode. An electronic semiconductor device that emits light when an electric current passes through it. They are considerably more efficient than incandescent bulbs, and rarely burn out. LEDs are used in many applications such as flat-screen video displays, and increasingly as general sources of light. See also semiconductor laser.