antigen
nounUK /ˈæn.tɪ.dʒən/
US /ˈæn.tɪ.dʒən/
A tiny thing that gets into your body and makes your body fight it.
The doctor said the virus has an antigen that the body learns to recognize.
RELATED WORDS
OTHER MEANINGS
2. A molecule on the surface of a cell that the immune system can identify.
Blood type is determined by antigens on the surface of red blood cells.
3. Any substance that triggers an allergic reaction.
Pollen acts as an antigen for people with hay fever.
4. A marker used in lab tests to detect disease.
The test looks for a specific antigen in the blood sample.