lactic acid

American  

noun

Biochemistry.

1. a colorless or yellowish, syrupy, water-soluble liquid, C 3 H 6 O 3 , produced during muscle contraction as a product of anaerobic glucose metabolism, abundant in sour milk, prepared usually by fermentation of cornstarch, molasses, potatoes, etc., or synthesized: used chiefly in dyeing and textile printing, as a flavoring agent in food, and in medicine.

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lactic acid British  

noun

1. Systematic name: 2-hydroxypropanoic acid.  a colourless syrupy carboxylic acid found in sour milk and many fruits and used as a preservative ( E270 ) for foodstuffs, such as soft margarine, and for making pharmaceuticals and adhesives. Formula: CH 3 CH(OH)COOH

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lactic acid Scientific  

/ lăk′tĭk /

1. A syrupy, water-soluble organic acid produced when milk sours or certain fruits ferment. It is also produced in the body during the anaerobic metabolism of glucose, as in muscle tissue during exercise, where its buildup can cause cramping pains. A synthetic form of lactic acid is used as a flavoring and preservative, in dyeing and textile printing, and in pharmaceuticals. Chemical formula: C ₃ H ₆ O ₃ .

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Etymology

Origin of lactic acid

First recorded in 1780–90

Example Sentences

See Examples For:

lactic acid

During fermentation, lactic acid bacteria broke down most of the lactose, leaving very little behind by the time the cheeses were ready to eat.

From Science Daily ● Aug. 17, 2026

“You’ve got lactic acid up to your eyeballs,” Porino said.

From The Wall Street Journal ● Feb. 6, 2026

The lactic acid, after some time, will cause the dough to smell like beer.

From Salon ● Sep. 25, 2025

This stops the stress hormone and lactic acid buildup that can hurt flavor and texture when fish are left to asphyxiate.

From Los Angeles Times ● Jul. 29, 2025

My entire body aches, especially my legs, which burn with lactic acid even when I am not moving.

From "Insurgent" by Veronica Roth