What does antibody mean?
An antibody is a specialized protein manufactured by the immune system to defend the body against foreign invaders such as viruses, bacteria, and toxins. Each antibody is designed to bind to one particular target — called an antigen — much like a key fits a specific lock, flagging the intruder for destruction by other immune cells or neutralizing it directly. Antibodies are produced by white blood cells known as B lymphocytes and remain in the blood and other bodily fluids, sometimes providing long-lasting protection after infection or vaccination. The word is most often encountered in medical and scientific contexts: doctors may order an antibody test to check whether someone has been exposed to a disease, and laboratories produce monoclonal antibodies as treatments for conditions ranging from autoimmune disorders to cancer. Since the COVID-19 pandemic, terms like 'antibody levels' have entered everyday conversation, making this once-specialized word a familiar part of public health vocabulary.
nounA protein produced by the immune system in response to a foreign substance (an antigen), which binds specifically to that substance to help neutralize or destroy it.
- A Y-shaped protein (immunoglobulin) made by B cells of the immune system that binds to a specific antigen to mark it for destruction or neutralize it directly.
"After vaccination, the body produces antibodies that recognize the virus and block infection."
"Blood tests showed she had developed antibodies to the measles virus after her childhood vaccination."
"Scientists engineered monoclonal antibodies in the laboratory to target cancer cells with remarkable precision."
Standard plural; far more common than the singular in general usage, since immunity typically involves many distinct antibodies.
"Vaccination stimulates the production of antibodies against future infection."
Your body can make billions of different antibodies — more than there are stars in the Milky Way — each shaped to lock onto one specific invader.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of antibody
The word 'antibody' was formed in English around the 1890s from the prefix 'anti-' (meaning 'against', from Greek) combined with 'body', referring to substances found in the body's fluids. It arose as German immunologists such as Paul Ehrlich developed theories of immunity, and the English term mirrored the German 'Antikörper'. It belongs to the same family of scientific coinages using 'anti-' as words like 'antitoxin' and 'antigen'.
How antibody is actually used
A scientific and medical term, common in both formal writing and everyday health discussion, especially since the COVID-19 pandemic popularized phrases like 'antibody test' and 'antibody levels'. Plural 'antibodies' is far more frequent than the singular in ordinary use. Not typically used figuratively outside medical contexts.
Easily confused with antibody
An antigen is the foreign substance that triggers an immune response, while an antibody is the protein the immune system produces in response to it.