phosphorous

American  

[fos-fer-uhs, fos-fawr-uhs, -fohr-] / ˈfɒs fər əs, fɒsˈfɔr əs, -ˈfoʊr- /

adjective

Chemistry.

1. containing trivalent phosphorus.

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phosphorous British  

/ ˈfɒsfərəs /

adjective

1. of or containing phosphorus in the trivalent state

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Other Word Forms

• nonphosphorous adjective

Etymology

Origin of phosphorous

First recorded in 1770–80; phosphor- + -ous

Example Sentences

The report from environment groups Size of Wales and WWF Cymru says the soy is high in phosphorous, and becomes a pollutant when animal manure spread on land runs off into rivers.

From BBC • Nov. 9, 2025

White phosphorous is considered an incendiary weapon under Protocol III of the Convention on the Prohibition of Use of Certain Conventional Weapons.

From Reuters • Oct. 12, 2023

Wastewater disposed in large bodies of water can result in high amounts of nitrogen and phosphorous, which can drive the growth of algae blooms.

From Los Angeles Times • Aug. 1, 2023

While the lake was less clean before, starting in the 2000s it was treated with nontoxic alum, a substance that reduces the phosphorous that can promote algae growth.

From Seattle Times • Jun. 2, 2023

Milkman’s left foot hovered above the floor, and Guitar’s eyes with their phosphorous lights singed his heart a little, but he took the stare.

From "Song of Solomon" by Toni Morrison