phosphor

noun

phos·​phor ˈfäs-fər How to pronounce phosphor (audio)
-ˌfȯr
variants or less commonly phosphore
ˈfäs-ˌfȯr How to pronounce phosphor (audio)
-fər
1
: a phosphorescent substance
2
: a luminescent substance that emits light when excited by radiation (such as electrons) and is used especially in fluorescent lamps and cathode-ray tubes

Examples of phosphor in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Similarly, their laser-phosphor light engine can't show laser speckle, which can be an issue for tri-color laser sources. — M. David Stone, PC Magazine, 17 May 2026 Afterglow phosphor particles absorb light and then release it slowly over time. — Laura Baisas, Popular Science, 27 Aug. 2025 Philips gets around this problem by putting the phosphor close to the outside of the bulb and illuminating it fairly evenly with a battalion of 18 LEDs. — IEEE Spectrum, 30 Dec. 2011 To make the fluorescent succulents, the team injected the plants with phosphor particles that can absorb energy from light at one wavelength, store some of it, and then re-emit it at another wavelength, similar to how glow-in-the-dark paint works. — Brendan Ruberry, semafor.com, 3 Sep. 2025 See All Example Sentences for phosphor

Word History

Etymology

Latin phosphorus, from Greek phōsphoros, literally, light bringer, from phōsphoros light-bearing, from phōs light + pherein to carry, bring — more at fancy, bear

First Known Use

1706, in the meaning defined at sense 1

Time Traveler
The first known use of phosphor was in 1706

Phrases Containing phosphor

Rhymes for phosphor

See All Rhymes for phosphor

Browse Nearby Words

phosphoprotein
phosphor
phosphoramidic acid
See all Nearby Words

Cite this Entry

“Phosphor.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phosphor. Accessed 7 Jul. 2026.

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Kids Definition

phosphor

noun
phos·​phor ˈfäs-fər How to pronounce phosphor (audio)
-ˌfȯ(ə)r
: a substance exhibiting phosphorescence

Medical Definition

phosphor

noun
phos·​phor ˈfäs-fər, -ˌfȯ(ə)r How to pronounce phosphor (audio)
variants also phosphore
-ˌfō(ə)r, -ˌfȯ(ə)r, -fər How to pronounce phosphor (audio)
: a phosphorescent substance
specifically : a substance that emits light when excited by radiation

More from Merriam-Webster on phosphor

Britannica.com: Encyclopedia article about phosphor

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