antigen[an′tə jən, -jen′]
- The definition of antigen is a harmful substance which enters the body which causes the body to make antibodies as a response to fight off disease.
An example of an antigen is a common cold virus which causes the body to make antibodies which help prevent the person from getting sick.
Origin of antigenanti- + -gen
- (immunology) A substance that induces an immune response, usually foreign.