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

This often occurs because the damage gluten causes to the small intestine can reduce lactase production, the enzyme needed to digest lactose. —Devineé Lingo, M.s., Health, 5 Oct. 2024

Some probiotics have prebiotics added, and some contain lactose. —Lainey Younkin, Ms, Rd, Health, 16 Sep. 2024

Hard and semi-hard cheeses have lower lactose in them. —Merve Ceylan, Health, 24 July 2024

Enzyme lactase: These medications, like Lactaid or Dairy Ease, are meant to help people with lactose intolerance digest foods with lactose and might help prevent protein farting related to lactose. —Cristina Mutchler, Health, 31 July 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