phosphorus

noun, often attributive phos·pho·rus \ ˈfäs-f(ə-)rəs \

Updated on: 21 Apr 2018

Definition of phosphorus

1 : a phosphorescent substance or body; especially : one that shines or glows in the dark

2 or less commonly phosphorous play \ˈfäs-f(ə-)rəs\ : a nonmetallic element of the nitrogen family that occurs widely especially as phosphates — see Chemical Elements Table

See phosphorus defined for English-language learners

See phosphorus defined for kids

Recent Examples of phosphorus from the Web

This 2,000-pound Mk84 bomb comes loaded with a mix of high explosive and white phosphorus.

— david hambling, Popular Mechanics, "These Are Syria's Chemical Weapons. Here's How To Destroy Them," 13 Apr. 2018
On average across Europe today, fertilizer contains about 32 milligrams of cadmium per kilogram (mg Cd/kg) of phosphorus, but the level can be as high as 200 mg Cd/kg, depending on where the phosphate rock is mined.

— natasha gilbert, Science | AAAS, "European Union debates controversial plans to limit cadmium in fertilizer," 10 Apr. 2018
The numbers on a container of fertilizer will tell you the percentages of available nitrogen, phosphorus and potassium found in the bag.

— amy hall, sandiegouniontribune.com, "Growing season ahead depends on proper feeding," 7 Mar. 2018
Of that group, almonds also contain the highest amounts of calcium, iron, magnesium, phosphorus, and zinc.

— jaclyn london, ms, rd, Good Housekeeping, "Why You Should Go Nuts About Almonds," 3 Apr. 2018
Morels are a good source of Vitamins B and D as well as minerals, including iron, copper, phosphorus, manganese, zinc and potassium.

— dwight adams, Indianapolis Star, "Morel mushrooms: Here's what you need to know," 3 Apr. 2018
Complete spring lawn feedings; select a low- or no-phosphorus fertilizer.

— tom maccubbin, OrlandoSentinel.com, "April in the garden," 31 Mar. 2018
Just seven months after landing, Curiosity analyzed a rock sample that contained sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon—the key chemical ingredients needed to sustain life.

— julissa treviño, Smithsonian, "Looking Back at Curiosity’s 2,000 Martian Days on the Red Planet," 22 Mar. 2018
Their proteins, once broken down, provide nutrients like nitrogen and phosphorus deficient in the soil.

— joanna klein, New York Times, "The Weird World Inside a Pitcher Plant," 7 Mar. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'phosphorus.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of phosphorus

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

NEW! Time Traveler

First Known Use: 1680

in the meaning defined at sense 1

See Words from the same year

PHOSPHORUS Defined for English Language Learners

phosphorus

noun

Definition of phosphorus for English Language Learners

chemistry : a poisonous chemical element that glows in the dark and burns when it is touched by air

PHOSPHORUS Defined for Kids

phosphorus

noun phos·pho·rus \ ˈfäs-fə-rəs \

Definition of phosphorus for Students

: a white or yellowish waxy chemical element that gives a faint glow in moist air

Medical Dictionary

phosphorus

noun, often attributive phos·pho·rus \ ˈfäs-f(ə-)rəs \

medical Definition of phosphorus

: 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