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

These substances support each plant’s roots and help the plant better absorb nutrients like phosphorus, nitrogen, and calcium through enriched water. —Rowan Briggs, The Mercury News, 14 Oct. 2024

These include vitamin C and B vitamins (like thiamine, riboflavin, niacin, and folate), calcium, phosphorus, magnesium, zinc, manganese, chromium, sodium, and potassium. —Megan Nunn, Verywell Health, 10 Oct. 2024

Three ounces of skipjack tuna, for example, contain iron, calcium, magnesium, phosphorus, zinc, thiamin, folate, vitamin B12, vitamin A, and a whopping 18 grams of protein, per the U.S. Department of Agriculture. —Daryl Austin, USA TODAY, 8 Oct. 2024

May Support Your Bones Calcium and phosphorus are the major components of the compound hydroxyapatite, which provides strength and structure to your bones. —Lauren O'Connor, Ms, Health, 29 Sep. 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