antigen

play
noun an·ti·gen \ˈan-ti-jən, -ˌjen\

Definition of antigen

  1. :  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

play \ˌan-ti-ˈje-nik\ adjective

antigenically

play \-ni-k(ə-)lē\ adverb

antigenicity

play \-jə-ˈni-sə-tē\ noun

Recent Examples of antigen from the Web

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.

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.

Origin and Etymology of antigen

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


ANTIGEN Defined for English Language Learners

antigen

play
noun

Definition of antigen for English Language Learners

  • medical : a harmful substance that causes the body to produce antibodies


Medical Dictionary

antigen

play
noun an·ti·gen \ˈant-i-jən\

Medical Definition of antigen

  1. :  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

\ˌant-i-ˈjen-ik\play adjective

antigenically

\-i-k(ə-)lē\play adverb

Illustration of antigen



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