: any of a large number of proteins of high molecular weight that are produced normally by specialized B cells after stimulation by an antigen and act specifically against the antigen in an immune response, that are produced abnormally by some cancer cells, and that typically consist of four subunits including two heavy chains and two light chains

called also immunoglobulin

Examples of antibody in a Sentence

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Think of Carvykti as a more specialized therapy, while Darzalex is an antibody used as a backbone treatment. Natasha Abellard, CNBC, 14 July 2026 People can carry the antibodies while not having any symptoms. Sophie Lindberg, Kansas City Star, 10 July 2026 Providers at Hospital of Central Connecticut ordered confirmatory lab work, and results revealed markedly high AChR antibodies supporting a diagnosis of myasthenia gravis, the suit states. Pamela McLoughlin, Hartford Courant, 9 July 2026 The disease in question is autoimmune gastritis, a chronic inflammatory condition in which antibodies destroy acid-producing cells in the stomach, which prevents people from absorbing iron. Sarah Todd, STAT, 8 July 2026 See All Example Sentences for antibody

Word History

First Known Use

1894, in the meaning defined above

Time Traveler
The first known use of antibody was in 1894

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Cite this Entry

“Antibody.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/antibody. Accessed 16 Jul. 2026.

Kids Definition

: a substance produced by special cells of the body that combines with an antigen and counteracts its effects or those of the microscopic plant or animal on which the antigen may occur

Medical Definition

plural antibodies
: any of a large number of proteins of high molecular weight that are produced normally by specialized B cells after stimulation by an antigen and act specifically against the antigen in an immune response, that are produced abnormally by some cancer cells, and that typically consist of four subunits including two heavy chains and two light chains

called also immunoglobulin

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