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

According to performance data, the battery delivers discharge power at –30 degrees Celsius that is three times higher than comparable lithium iron phosphate systems. —Jijo Malayil, Interesting Engineering, 6 Feb. 2026

My research—including an interview with a poultry science professor—led me to the conclusion that sodium phosphate, commonly used to make chickens extra juicy, could be a credible culprit for the soapy profile. —Li Goldstein, Bon Appetit Magazine, 6 Feb. 2026

Out of that awakening came important measures to counteract giant algae blooms by stopping the use of phosphates in dishwashing liquid and other household items. —Theodore J. Karamanski, Chicago Tribune, 6 Feb. 2026

Two California shoppers filed a class action complaint accusing Costco of falsely advertising its rotisserie chicken as preservative-free despite containing sodium phosphate and carrageenan. —Clara Harter, Los Angeles Times, 29 Jan. 2026

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)