|the past tense and past participle of lead|
|LED (ěl'ē-dē', lěd) Pronunciation Key
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.