lactose

noun

lac·​tose ˈlak-ˌtōs 

-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

These foods include certain dairy products containing lactose and certain carbohydrates including fruit sugar (fructose).13 How to Get an Endometriosis Diagnosis Summary Endo belly is severe lower-abdominal swelling caused by endometriosis. —Michelle Pugle, Verywell Health, 4 Nov. 2024

Goat milk has a similar protein and lactose content to cow's milk. —Isabel Vasquez Rd Ldn, Health, 2 Nov. 2024

For cats that have trouble processing lactose, what does this mean for their consumption of other dairy products? —Olivia Munson, USA TODAY, 12 Oct. 2024

Goat milk does have lactose and isn’t suitable for people with lactose intolerance. —Isabel Vasquez Rd Ldn, Health, 2 Nov. 2024

Word History

Etymology

International Scientific Vocabulary

First Known Use

1847, in the meaning defined above

Phrases Containing lactose

• lactose intolerant

Kids Definition

lactose

noun

lac·​tose ˈlak-ˌtōs 

: 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

lac·​tose ˈlak-ˌtōs, -ˌtōz 

: 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