antigen

noun
an·​ti·​gen | \ ˈan-ti-jən How to pronounce antigen (audio) , -ˌjen \

Definition of antigen

: 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

Other Words from antigen

antigenic \ ˌan-​ti-​ˈje-​nik How to pronounce antigen (audio) \ adjective
antigenically \ ˌan-​ti-​ˈje-​ni-​k(ə-​)lē How to pronounce antigen (audio) \ adverb
antigenicity \ ˌan-​ti-​jə-​ˈni-​sə-​tē How to pronounce antigen (audio) \ 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 These symptoms can look like bad allergies or the flu, so experts say use an antigen test after symptoms start. Josh Fischman, Scientific American, 16 May 2022 Unvaccinated travelers must undergo a 7-day quarantine and take a rapid antigen test on the last day. Alison Fox, Travel + Leisure, 12 May 2022 The association instituted multiple COVID protocols for the dinner, requiring attendees to be fully vaccinated and present a same-day negative antigen test. Victoria Albert, CBS News, 6 May 2022 Charness and his team are also encouraging their patients to start their isolation period over again and stay away until their antigen test is negative. Arielle Mitropoulos, ABC News, 5 May 2022 These results, McDonald said, should inform the decisions that patients make after an antigen test. Paul Sisson, San Diego Union-Tribune, 5 May 2022 Harris took a rapid antigen test Tuesday morning after going to work at the White House, Allen said. Noah Biermanstaff Writer, Los Angeles Times, 26 Apr. 2022 In the new study, Paxlovid or placebo was given to 2,957 adults who had a negative rapid antigen test and were asymptomatic, but who were living with someone who had Covid. Matthew Herper, STAT, 4 May 2022 Attendees at the dinner were required to show proof of vaccination and a same-day negative Covid antigen test. Paul Leblanc And Oliver Darcy, CNN, 3 May 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'antigen.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of antigen

1908, in the meaning defined above

History and Etymology for antigen

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

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Time Traveler for antigen

Time Traveler

The first known use of antigen was in 1908

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Dictionary Entries Near antigen

antigay

antigen

antigenic determinant

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Statistics for antigen

Last Updated

19 May 2022

Cite this Entry

“Antigen.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/antigen. Accessed 22 May. 2022.

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More Definitions for antigen

antigen

noun
an·​ti·​gen | \ ˈant-i-jən How to pronounce antigen (audio) \

Medical Definition of antigen

: 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

Other Words from antigen

antigenic \ ˌant-​i-​ˈjen-​ik How to pronounce antigen (audio) \ adjective
antigenically \ -​i-​k(ə-​)lē How to pronounce antigen (audio) \ adverb

More from Merriam-Webster on antigen

Nglish: Translation of antigen for Spanish Speakers

Britannica English: Translation of antigen for Arabic Speakers

Britannica.com: Encyclopedia article about antigen

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