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

Israel has used white phosphorus, a highly flammable chemical that ignites upon contact with oxygen, in violation of international law, devastating the area’s environment and agricultural land. —Maha Yahya, Foreign Affairs, 20 Nov. 2024

For those who are intolerant to dairy products or those who are vegan, almonds are a great source of calcium and phosphorus. —Jeanne Ballion, Vogue, 31 Oct. 2024

The tsunamis would have dragged in even more phosphorus from the land, as well as churned up iron, an important energy source for some microorganisms, from deep-sea layers. —Margherita Bassi, Smithsonian Magazine, 25 Oct. 2024

This will often involve reducing protein, sodium, potassium, phosphorus, and high-fat foods and eating more fruits, vegetables, lean meats, and low-fat or fat-free dairy products.2223 Exercise regularly: Aim for at least 30 minutes of physical activity most days of the week. —Lindsay Curtis, Health, 30 Nov. 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