phosphate

noun

phos·​phate ˈfäs-ˌfāt How to pronounce phosphate (audio)
1
a(1)
: a salt or ester of a phosphoric acid
(2)
: the trivalent anion PO43− derived from phosphoric acid H3PO4
b
: an organic compound of phosphoric acid in which the acid group is bound to nitrogen or a carboxyl group in a way that permits useful energy to be released (as in metabolism)
2
: an effervescent drink of carbonated water with a small amount of phosphoric acid flavored with fruit syrup
3
: a phosphatic material used for fertilizers

Examples of phosphate in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Modern lithium iron phosphate (LFP) batteries commonly exceed 200 watt-hours per kilogram, while nickel-rich lithium chemistries can achieve even higher values. — Kaif Shaikh, Interesting Engineering, 2 Aug. 2026 This range comes courtesy of a 65-kWh lithium-iron-phosphate (LFP) battery. — New Atlas, 2 Aug. 2026 Ensure the product is free from harsh ingredients, such as ammonia, petroleum, phosphates, phthalates, and parabens, and meets the Environmental Protection Agency’s Safer Choice Standard. — Madeline Buiano, Martha Stewart, 31 July 2026 Similar salt levels in briny fluids can preserve the chemical compound phosphate in a solution, which may then kickstart chemical reactions between minerals and organic materials. — Andrew Paul, Popular Science, 15 July 2026 See All Example Sentences for phosphate

Word History

Etymology

French, from acide phosphorique phosphoric acid

First Known Use

1788, in the meaning defined at sense 1a(1)

Time Traveler
The first known use of phosphate was in 1788

Phrases Containing phosphate

Rhymes for phosphate

See All Rhymes for phosphate

Browse Nearby Words

phosphatase
phosphate
phosphated flour
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Cite this Entry

“Phosphate.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/phosphate. Accessed 9 Aug. 2026.

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Kids Definition

phosphate

noun
phos·​phate ˈfäs-ˌfāt How to pronounce phosphate (audio)
1
: a salt of a phosphoric acid
2
: a drink made of carbonated water and fruit syrup with a little phosphoric acid added for tang

Medical Definition

phosphate

noun
phos·​phate ˈfäs-ˌfāt How to pronounce phosphate (audio)
1
a
: a salt or ester of a phosphoric acid
b
: the trivalent anion PO43− derived from phosphoric acid H3PO4
2
: an organic compound of phosphoric acid in which the acid group is bound to nitrogen or a carboxyl group in a way that permits useful energy to be released (as in metabolism)

More from Merriam-Webster on phosphate

Nglish: Translation of phosphate for Spanish Speakers

Britannica.com: Encyclopedia article about phosphate

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