indicator light-emitting diode

indicator

— noun (= index) a number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time — noun a signal for attracting attention — noun a device for showing the operating condition of some system — noun (chemistry) a substance that changes color to indicate the presence of some ion or substance; can be used to indicate the completion of a chemical reaction or (in medicine) to test for a particular reaction

light Noun

— The energy that our eyes sense is light. And dance by the light of the moon.—Buffalo Gals, American folksong — If someone talks about a light, he or she means something bright that can be seen. The lights of the city shine all over the valley. When you leave the room, turn off the light.

light Adjective

— Something that is light in color is close to white. The morning sky was very light. — Something that is light in weight does not weigh much. I lifted her easily because she was so light. — Light may also mean that something is not serious. The light bruise on my leg didn't hurt much. I enjoy light comedy, where lots of funny things happen.

light Verb

— If someone lights a fire, the fire starts to burn. Let's light the wood in the fireplace. The match lit and I could see around me. — Something that lights a place makes it less dark. The moon lighted the forest path.

emit Verb

— If something emits gas, light, sound, etc., it sends it out. The sun emits hot rays.

diode

— noun a semiconductor that consists of a p-n junction — noun a thermionic tube having two electrodes; used as a rectifier