lactic acid

noun

: a hygroscopic organic acid C₃H₆O₃ present normally especially in muscle tissue as a by-product of anaerobic glycolysis, produced in carbohydrate matter usually by bacterial fermentation, and used especially in food and medicine and in industry

Examples of lactic acid in a Sentence

Recent Examples on the Web

Ingredients like mandelic acid, lactic acid, and salicylic acid gently exfoliate and brighten up the complexion. —Venus Wong, refinery29.com, 10 Oct. 2024

This body lotion is formulated with 10 percent lactic acid, providing additional chemical exfoliation benefits and an excellent way to continue treating the skin between body scrub usage. —Jessie Quinn, StyleCaster, 15 Aug. 2024

Grimes recommends starting with using a product with lactic acid once and twice a week. —Larry Stansbury, Essence, 14 Aug. 2024

Because the thin air at altitude did not allow enough oxygen to be absorbed by the body, lactic acid was produced earlier, and at slower speeds, leading to poor muscular recovery. —Kevin Baxter, Los Angeles Times, 18 July 2024

Word History

First Known Use

1790, in the meaning defined above

Kids Definition

lactic acid

noun

lac·​tic acid

ˌlak-tik-

: an organic acid present especially in muscle tissue as a result of the breakdown of carbohydrates (as glycogen), is made from carbohydrates usually by fermentation by bacteria, and is used especially in food and medicine

Medical Definition

lactic acid

noun

: a hygroscopic organic acid C₃H₆O₃ that is known in three optically isomeric forms:

a

or D-lactic acid

ˈdē- 

: the dextrorotatory form present normally in blood and muscle tissue as a product of the anaerobic metabolism of glucose and glycogen

b

or L-lactic acid

ˈel- 

: the levorotatory form obtained by biological fermentation of sucrose

c

or DL-lactic acid

ˈdē-ˈel- 

: the racemic form present in food products and made usually by bacterial fermentation (as of whey or raw sugar) but also synthetically, and used chiefly in foods and beverages, in medicine, in tanning and dyeing, and in making esters for use as solvents and plasticizers