per·​ox·​i·​dase pə-ˈräk-sə-ˌdās How to pronounce peroxidase (audio)
: an enzyme that catalyzes the oxidation of various substances by peroxides

Example Sentences

Recent Examples on the Web Erythrocyte reduced glutathione levels, erythrocyte glutathione peroxidase and superoxide dismutase activities were significantly increased in the rats kept in the pyramid as compared to the other two groups. Ncbi Rofl, Discover Magazine, 22 Feb. 2012 Antibodies to thyroid peroxidase are found in about 20% of healthy women, up to 40% of people with Type 1 diabetes, and in 90% to 100% of people with autoimmune thyroiditis (Hashimoto’s thyroiditis). Dr. Keith Roach, oregonlive, 10 June 2022

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

Word History

First Known Use

1900, in the meaning defined above

Time Traveler
The first known use of peroxidase was in 1900

Dictionary Entries Near peroxidase

Cite this Entry

“Peroxidase.” Dictionary, Merriam-Webster, Accessed 5 Jun. 2023.

Medical Definition


per·​ox·​i·​dase pə-ˈräk-sə-ˌdās, -ˌdāz How to pronounce peroxidase (audio)
: an enzyme occurring especially in plants, milk, and white blood cells and consisting of a protein complex with hematin groups that catalyzes the oxidation of various substances by peroxides

More from Merriam-Webster on peroxidase

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!