Phosphor

Part of speech: noun

Pronunciation: /ˈfɒsfə/

Definitions

1. A light-emitting chemical element found in various applications A luminescent material employed in technologies for visible light generation A compound that exhibits brightness when activated by external energy sources
2. A material that glows or radiates light in response to stimulation such as exposure to electrons or ultraviolet rays
3. A chemical that produces visible light by giving off energy after being energized by an external source

Etymology: The word's core sense is much older than the element that now bears its name. Its Greek ancestor, "phōsphoros," meant "light-bringing" or "bringer of light": "phōs" (light) joined to "-phoros" (bringing, bearing). It was the name the Greeks gave to the morning star, the planet Venus when it rises before the sun, and the Latin "Lucifer" carried the same sense. The word reached English through Medieval Latin "phosphorus," which kept that meaning of a light-bearing body. Its modern chemical sense came much later. In the 1600s, alchemists and experimenters noticed that certain substances glowed in the dark, and when the element we now call phosphorus was isolated, it was named for its glow, since it shines faintly when exposed to air. The name thus moved from a star in the sky to a substance on the laboratory bench. From there, the word broadened again. Today it covers any material that gives off light, such as the coatings inside older screens and the luminescent compounds used in lamps. Each step kept the original idea of light being carried or released.

Synonyms: phosphorescent material, luminescent substance, light-emitting compound