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

Definition of phosphorus 

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 that occurs widely especially as phosphates — see Chemical Elements Table

Examples of phosphorus in a Sentence

Recent Examples on the Web

State environmental regulators set the limit for the amount of phosphorus coming into the lake, but the amount is regularly far more than the lake can handle. Jenny Staletovich, miamiherald, "Massive and toxic algae bloom threatens Florida coasts with another lost summer," 29 June 2018 Peas, beans, and other legumes add nitrogen to the soil but need lots of phosphorus. The Editors Of Organic Life, Good Housekeeping, "How Crop Rotation Can Help You Manage Pests And Improve Soil Quality," 23 Feb. 2017 But add pollution — the phosphorus and nitrogen from farm fields and leaky septic tanks — and good turns to bad, fueling explosive blooms. Jenny Staletovich, miamiherald, "What’s an algae bloom and how did it wind up sliming Florida’s biggest lake?," 10 July 2018 Finnegan said some years the district won’t use any phosphorus on park land. Suzanne Baker, Naperville Sun, "Naperville girls have the poop on best pond-friendly lawn fertilizer," 3 July 2018 Previous studies have found that half the phosphorus in the lake in the summer comes from human urine. Martin Finucane,, "Stop peeing in Walden Pond, researchers beg," 5 Apr. 2018 Apply a fertilizer with a high percentage of nitrogen and without any phosphorus (first and second numbers of the fertilizer analysis respectively). Neil Sperry, star-telegram, "Here’s your gardening to-do list for the second part of the summer," 11 July 2018 This lack of oxygen is generally caused by an excessive amount of nitrogen and phosphorus in the water, which causes an overgrowth of algae. Mi Clear, Detroit Free Press, "MI CLEAR brings together diverse groups to reduce algae blooms in Lake Erie," 20 June 2018 Nitrogen and phosphorus can end up in the river from sources such as agricultural runoff and sewage treatment plants. Washington Post, "Energy company challenges new requirements for Maryland dam," 1 June 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.

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First Known Use of phosphorus

1680, in the meaning defined at sense 1

History and Etymology for phosphorus

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

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Last Updated

19 Oct 2018

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Time Traveler for phosphorus

The first known use of phosphorus was in 1680

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English Language Learners Definition of phosphorus

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


phos·​pho·​rus | \ˈfäs-fə-rəs \

Kids Definition of phosphorus

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


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

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More from Merriam-Webster on phosphorus

Spanish Central: Translation of phosphorus

Nglish: Translation of phosphorus for Spanish Speakers

Britannica English: Translation of phosphorus for Arabic Speakers Encyclopedia article about phosphorus

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full of whispering sounds

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