antigen

noun

an·​ti·​gen ˈan-ti-jən How to pronounce antigen (audio)
-ˌjen
: any substance (such as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (such as a protein) and that is capable of binding with a product (such as an antibody or T cell) of the immune response
antigenic adjective
antigenically adverb
antigenicity noun

Did you know?

An antibody is a protein produced by your immune system to fight outside invaders. Since the enemy substance actually triggers the production of antibodies, such substances are called antigens—anti- being short for antibody, and -gen meaning "producer". (In a similar way, an allergen produces an allergy, and a pathogen produces a pathology or disease.) Antigens are often rodlike structures that stick out from the surface of an invading organism—usually a bacterium or a virus—and allow it to attach itself to cells in the invaded body. But unfortunately for them, in doing so they let the immune system know they're present, and the body is flooded with an army of Pac-Man-like antibodies.

Examples of antigen in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Greywolf Therapeutics, an antigen modulation technology developer, Darlene Deptula-Hicks as CFO. Ellie Austin, Fortune, 20 Nov. 2024 Hugh Mason, an associate professor at Arizona State University who has been studying the use of plants for the production of vaccine antigens for more than 30 years, said there are significant technical hurdles to delivering a precise amount of a vaccine in a piece of fruit or a vegetable. Nate Trela, USA TODAY, 26 Sep. 2024 AstraZeneca later redesigned the antigens in the vaccine, earning back the CDC's recommendation starting in 2018. Alexander Tin, CBS News, 20 Sep. 2024 Advancing rapid antigen tests Like all technologies, rapid antigen tests have limitations. Julie Sullivan, The Conversation, 8 Oct. 2024 See all Example Sentences for antigen 

Word History

Etymology

German, from French antigène, from anticorps antibody + -gène -gen

First Known Use

1908, in the meaning defined above

Time Traveler
The first known use of antigen was in 1908

Dictionary Entries Near antigen

Cite this Entry

“Antigen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/antigen. Accessed 5 Dec. 2024.

Kids Definition

antigen

noun
an·​ti·​gen ˈant-i-jən How to pronounce antigen (audio)
-ˌjen
: a substance (as a protein) that causes the body to form antibodies against it when it is introduced into the body either alone or as part of a microscopic plant or animal
antigenic adjective

Medical Definition

antigen

noun
an·​ti·​gen ˈant-i-jən How to pronounce antigen (audio)
: any substance (as an immunogen or a hapten) foreign to the body that evokes an immune response either alone or after forming a complex with a larger molecule (as a protein) and that is capable of binding with a product (as an antibody or T cell) of the immune response
antigenic adjective
antigenically adverb

More from Merriam-Webster on antigen

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