lactase

noun

lac·​tase ˈlak-ˌtās 

-ˌtāz

: an enzyme that hydrolyzes beta-galactosides (such as lactose) and occurs especially in the intestines of young mammals and in yeasts

Examples of lactase in a Sentence

Recent Examples on the Web

The infection damages the gut lining, leading to a lack of lactase, the enzyme that breaks down lactose. —Adrianna Rodriguez, USA TODAY, 7 Jan. 2025

Normally digested by the body with an enzyme called ‘lactase’, this sugar breaks down into lactic acid to feed the healthy bacteria in our intestinal microbiota. —Marie Bladt, Vogue, 24 Dec. 2024

Trouble with lactose intolerance tends to begin in adulthood, when our bodies gradually makes less lactase, an enzyme that breaks down lactose. —Caroline Hopkins Legaspi, New York Times, 24 Dec. 2024

Proponents argue that raw milk produces its own lactase thanks to beneficial bacteria, or probiotics. —Jeffrey Kluger, TIME, 20 Dec. 2024

Word History

Etymology

International Scientific Vocabulary

First Known Use

1891, in the meaning defined above

Kids Definition

lactase

noun

lac·​tase ˈlak-ˌtās 

: an enzyme that breaks down lactose and related compounds and occurs especially in the intestines of young mammals and in yeasts

Medical Definition

lactase

noun

lac·​tase ˈlak-ˌtās, -ˌtāz 

: an enzyme that hydrolyzes especially lactose to glucose and galactose and occurs especially in the intestines of young mammals and in yeasts