phosphate

American  

[fos-feyt] / ˈfɒs feɪt /

noun

1. Chemistry.

   1. (loosely) a salt or ester of phosphoric acid.

   2. a tertiary salt of orthophosphoric acid, as sodium phosphate.

2. Agriculture. a fertilizing material containing compounds of phosphorus.

3. a carbonated drink of water and fruit syrup containing a little phosphoric acid.

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phosphate British  

/ ˈfɒsfeɪt, fɒsˈfætɪk /

noun

1. any salt or ester of any phosphoric acid, esp a salt of orthophosphoric acid

2. (often plural) any of several chemical fertilizers containing phosphorous compounds

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phosphate Scientific  

/ fŏs′fāt′ /

1. A salt or ester of phosphoric acid, containing the group PO ₄. Phosphates are important in metabolism and are frequently used in fertilizers.

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Other Word Forms

• phosphatic adjective
• subphosphate noun

Etymology

Origin of phosphate

First recorded in 1785–95; phosph- + -ate ²

Example Sentences

In testing, the artificial saliva spray reduced bacterial activity and slowed tooth demineralization -- the process by which teeth lose calcium and phosphate, making them more vulnerable to cavities.

From Science Daily • Apr. 5, 2026

Although the U.S. has a robust fertilizer manufacturing industry, the country still relies on nitrogen and phosphate imports to meet demand, Milam adds.

From Barron's • Mar. 29, 2026

Late last year, cash-strapped American farmers cut back on fertilizer purchases, according to Mosaic, which mines potash in western Canada and phosphate in central Florida.

From The Wall Street Journal • Mar. 12, 2026

In a statement to USA Today, Costco explained that it uses carrageenan and sodium phosphate “to support moisture retention, texture, and product consistency during cooking,” adding that both ingredients are “approved by food safety authorities.”

From Salon • Feb. 26, 2026

The phosphate backbone twisted inside, like the central shaft of a spiral staircase, with its treads facing out.

From "The Gene" by Siddhartha Mukherjee