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

ˈfäs-f(ə-)rəs 

: 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

Just 26 grams of Nori seaweed, for instance, packs 1.5 grams of protein, 92 milligrams of potassium, 18 milligrams of calcium, 15 milligrams of phosphorus, and 10 milligrams of vitamin C, per the U.S. Department of Agriculture. —Daryl Austin, USA TODAY, 8 Sep. 2024

Its colors come from the composition of different atmospheric layers, which are individually made of ammonia, water ice, sulfur and phosphorus gases, according to NASA. —Ashley Strickland, CNN, 22 June 2024

Nitrogen and phosphorus pollution in runoff and discharges from agricultural and urban areas are the major contributors to the annual summer hypoxic dead zone in the Gulf of Mexico. —Li Cohen, CBS News, 14 June 2024

Stormwater drives bacterial growth by washing phosphorus and nitrogen into lakes and rivers, where heat waves can drive bacteria and algae growth. —Christiaan Hetzner, Fortune, 17 Aug. 2024

Word History

Etymology

New Latin, from Greek phōsphoros light-bearing — more at phosphor

First Known Use

1680, in the meaning defined at sense 1

Kids 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

fäs-ˈfȯr-ik

-ˈfär-

adjective

phosphorous

ˈfäs-f(ə-)rəs;

fäs-ˈfōr-əs

-ˈfȯr-

adjective

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