lactose

noun

lac·​tose ˈlak-ˌtōs How to pronounce lactose (audio)
-ˌtōz
: a disaccharide sugar C12H22O11 that is present in milk and yields glucose and galactose upon hydrolysis and yields especially lactic acid upon fermentation

Examples of lactose in a Sentence

Recent Examples on the Web Certain medical conditions, such as celiac disease or inflammatory bowel disease, can lead to secondary lactose intolerance. Erica Lamberg, Fox News, 8 Feb. 2024 This enzyme breaks down the lactose sugar into two smaller, digestible components. USA TODAY, 31 Jan. 2024 Sugars like fructose, sucrose, and dietary glucose are found naturally in many fruits and vegetables, while maltose is found in many grains and lactose is found in dairy products, per Harvard Medical School. Daryl Austin, USA TODAY, 27 Feb. 2024 Someone can be intolerant to the lactose in milk, but will not have an immune response. Sheah Rarback, Miami Herald, 9 Feb. 2024 Fruit sugar is often referred to as fructose just as the sugar in milk is most often listed as lactose. Caitlin Granfield, Miami Herald, 30 Jan. 2024 Most of these bacteria are fermenters, capable of digesting sugars like lactose anaerobically, or without oxygen. Max Bennett, Discover Magazine, 29 Jan. 2024 Lactose intolerance is the inability to fully digest the sugar (lactose) in milk and milk products. Brierley Horton, Ms, Better Homes & Gardens, 14 Jan. 2024 Josh Belinsky, the 28-year-old who’s got milk —minus the lactose. Chloe Sorvino, Forbes, 28 Nov. 2023

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'lactose.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

Etymology

International Scientific Vocabulary

First Known Use

1847, in the meaning defined above

Time Traveler
The first known use of lactose was in 1847

Dictionary Entries Near lactose

Cite this Entry

“Lactose.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/lactose. Accessed 19 Mar. 2024.

Kids Definition

lactose

noun
lac·​tose ˈlak-ˌtōs How to pronounce lactose (audio)
: a sugar present in milk that breaks down to give glucose and galactose and on fermentation gives especially lactic acid

called also milk sugar

Medical Definition

lactose

noun
: a disaccharide sugar C12H22O11 that is present in milk, yields glucose and galactose upon hydrolysis, yields especially lactic acid upon fermentation, and is used chiefly in foods, medicines, and culture media (as for the manufacture of penicillin)

called also milk sugar

More from Merriam-Webster on lactose

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