phosphate

noun

phos·​phate ˈfäs-ˌfāt 

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

As our cells use ATP, this molecule loses a tiny unit called a phosphate (made of phosphorus and oxygen). —Matt Fuchs, Time, 2 Sep. 2025

On the flip side, iron and phosphate aren’t worth much compared to nickel or cobalt, making LFP batteries less attractive from a recycling perspective, according to researchers. —Prabhat Ranjan Mishra, Interesting Engineering, 28 Aug. 2025

Consider using a commercial bait containing iron phosphate. —Arricca Elin Sansone, Southern Living, 28 Aug. 2025

To fill the droplets, cells use a production line known as the glycerol-3-phosphate (G-3-P) pathway. —New Atlas, 28 Aug. 2025

Word History

Etymology

French, from acide phosphorique phosphoric acid

First Known Use

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

Phrases Containing phosphate

• ammonium phosphate
• calcium phosphate
• creatine phosphate
• diammonium phosphate
• disodium phosphate
• glucose phosphate
• glucose-6-phosphate dehydrogenase
• nicotinamide adenine dinucleotide phosphate
• phosphate rock
• trisodium phosphate

Rhymes for phosphate

• bisphosphate
• diphosphate
• triphosphate
• glycerophosphate
• organophosphate
• metaphosphate
• monophosphate
• orthophosphate
• polyphosphate
• pyrophosphate
• superphosphate

Kids Definition

phosphate

noun

phos·​phate ˈfäs-ˌfāt 

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 

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)