antibody
Americannoun
-
antibodies
plural
-
any of numerous Y -shaped protein molecules produced by B cells as a primary immune defense, each molecule and its clones having a unique binding site that can combine with the complementary site of a foreign antigen, as on a virus or bacterium, thereby disabling the antigen and signaling other immune defenses. Ab
-
antibodies of a particular type collectively.
noun
-
Any of numerous proteins produced by B lymphocytes in response to the presence of specific foreign antigens, including microorganisms and toxins. Antibodies consist of two pairs of polypeptide chains, called heavy chains and light chains, that are arranged in a Y-shape. The two tips of the Y are the regions that bind to antigens and deactivate them.
-
Also called immunoglobulin
Closer Look
Like other vertebrates, humans possess an effective immune system that uses antibodies to fight bacteria, viruses, and cancer cells. Antibodies are complex, Y-shaped protein molecules. The immune system's B lymphocytes, which are produced by the bone marrow, develop into plasma cells that can generate a huge variety of antibodies, each one capable of combining with and destroying an antigen, a foreign molecule. Antibodies react to very specific characteristics of different antigens, binding them to the top ends of their Y formation. Once the antibody and antigen combine, the antibodies deactivate the antigen or lead it to macrophages(a kind of white blood cell) that ingest and destroy it. High numbers of a particular antibody may persist for months after an invasion, eventually diminishing. However, the B cells can quickly manufacture more of the same antibody if exposure to the antigen recurs. Vaccines work by “training” B cells to recognize and react quickly to potential disease molecules.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of antibody
Compare meaning
How does antibody compare to similar and commonly confused words? Explore the most common comparisons:
Explanation
An antibody is a protein made by the body that latches onto foreign bacteria and viruses to make them ineffective. Each antibody is designed to target a particular opponent. A powerful part of the body’s immune system, an antibody is produced when the body senses an invader — called an antigen that it doesn’t think should be there. The body then sends out the antibody to neutralize it. Don’t think of an antibody as being anti or “against” your body; think of the body in the word antibody as the antigen, or foreign body that is being fought. Known antibodies have been especially useful in the creation of vaccines.
Vocabulary lists containing antibody
This Week In Words: May 3–9, 2020
Looking to grow your vocabulary? Check out this interactive, curated word list from our team of English language specialists at Vocabulary.com – one of over 17,000 lists we've built to help learners worldwide!
Florida's B.E.S.T. Common Prefixes: ant-, anti-
Interested in learning more words like this one? Our team at Vocabulary.com has got you covered! You can review flashcards, quiz yourself, practice spelling, and more – and it's all completely free to use!
The ACT Science Test: Biology Review 2
Want to remember this word for good? Start your learning journey today with our library of interactive, themed word lists built by the experts at Vocabulary.com – we'll help you make the most of your study time!
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
“It really paves the way for the multiple other antibody drug conjugates that we have in our portfolio.”
From The Wall Street Journal ● Oct. 26, 2026
People who later developed Crohn's disease or ulcerative colitis had significantly less antibody diversity than healthy participants, meaning their immune systems showed a narrower range of antibody responses.
From Science Daily ● Oct. 24, 2026
The researchers then used machine learning, a form of artificial intelligence that identifies patterns in complex data, to determine whether these antibody signatures could distinguish people who would eventually develop IBD from healthy individuals.
From Science Daily ● Oct. 24, 2026
At the same time, antibody responses to encapsulated bacteria gradually decreased as diagnosis approached.
From Science Daily ● Oct. 24, 2026
It has recently been learned that the genes for the marking of self by cellular antigens and those for making immunologic responses by antibody formation are closely linked.
From "The Lives of a Cell" by Lewis Thomas
“We suspect the reason is that influenza antibodies are shaped by lifetime exposure histories,” Bloom said.
From The Wall Street Journal ● Oct. 30, 2026
Researchers believe the results provide a foundation for developing a blood test that identifies people whose disease is associated with antibodies against IL-10.
From Science Daily ● Oct. 26, 2026
Existing scorpion antivenoms are produced by injecting horses with venom and harvesting their plasma antibodies, making them expensive to produce, variable and effective only against specific species.
From MarketWatch ● Oct. 20, 2026
They also intend to measure antibodies against Neu5Gc directly.
From Science Daily ● Oct. 18, 2026
Through this encounter with the fever their blood automatically produced antibodies that either fought off the yellow fever virus entirely or reduced its impact on the individual significantly.
From "An American Plague: The True and Terrifying Story of the Yellow Fever Epidemic of 1793" by Jim Murphy
Random Word
Spin the wheel and learn a new word!
Get a wordDefinitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
