Antibody (noun)

1. A protein produced by the body's immune system when it detects harmful substances, such as bacteria, viruses, and toxins.
2. A substance that can react with a specific antigen to neutralize or destroy it.

Origin:

Late 19th century: from anti- + body.

Examples:

1. The vaccine triggers the production of antibodies to protect against the disease.
2. The patient's blood test showed a high level of antibodies to the virus.
3. Antibodies are proteins that are produced by the body to fight off infections.
4. The body's production of antibodies can take several weeks after exposure to an antigen.
5. The patient's antibodies were able to neutralize the toxins produced by the bacteria.