phosphorus
noun
phos·pho·rus
ˈfäs-f(ə-)rəs 
often attributive
1
: a phosphorescent substance or body
especially
: one that shines or glows in the dark
2
or less commonly phosphorous
: a nonmetallic element of the nitrogen family with atomic number 15 that occurs widely in combination especially as phosphates, that is essential for life in all known organisms, and that is used especially in fertilizers and organophosphorus compounds see Chemical Elements Table
Examples of phosphorus in a Sentence
Recent Examples on the Web
Potassium, along with nitrogen and phosphorus, became one of the three key nutrients in modern fertilizer, and demand for it soared.
—
Made By History, Time, 15 Apr. 2025
Nutrients and Watering Cannabis plants are hungry for nutrients, especially nitrogen, phosphorus, and potassium.
—Matt Rozo, Mercury News, 11 Apr. 2025
While some biodegradable plastics can still leave behind harmful microplastics, this material breaks down into nitrogen and phosphorus, which are useful nutrients for plants and microbes.
—Michael Irving, New Atlas, 27 Mar. 2025
For example, salt can release nitrogen or phosphorus from sediments in a watershed, which act as nutrients for plants—potentially leading to an overgrowth of algae and bacteria in the system, Kaushal said.
—Ars Technica, 19 Mar. 2025
See All Example Sentences for phosphorus
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Made By History, Time, 15 Apr. 2025
Nutrients and Watering Cannabis plants are hungry for nutrients, especially nitrogen, phosphorus, and potassium.
—Matt Rozo, Mercury News, 11 Apr. 2025
While some biodegradable plastics can still leave behind harmful microplastics, this material breaks down into nitrogen and phosphorus, which are useful nutrients for plants and microbes.
—Michael Irving, New Atlas, 27 Mar. 2025
For example, salt can release nitrogen or phosphorus from sediments in a watershed, which act as nutrients for plants—potentially leading to an overgrowth of algae and bacteria in the system, Kaushal said.
—Ars Technica, 19 Mar. 2025
See All Example Sentences for phosphorus
Cite this Entry
“Phosphorus.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phosphorus. Accessed 21 Apr. 2025.
Copy CitationKids Definition
phosphorus
noun
phos·pho·rus
ˈfäs-f(ə-)rəs
1
: a phosphorescent substance
especially
: one that glows in the dark
2
: a nonmetallic element that occurs widely especially as phosphates see element
phosphoric
adjective
fäs-ˈfȯr-ik
-ˈfär-
phosphorous
adjective
ˈfäs-f(ə-)rəs;
fäs-ˈfōr-əs
-ˈfȯr-
Medical Definition
phosphorus
noun
phos·pho·rus
ˈfäs-f(ə-)rəs
often attributive
: a nonmetallic multivalent element that occurs widely in combined form especially as inorganic phosphates in minerals, soils, natural waters, bones, and teeth and as organic phosphates in all living cells and that exists in several allotropic forms
—symbol P
see Chemical Elements Table
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