The story
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: A characteristic shared by a group of immunoglobulin or T-cell receptor molecules, based on the antigen-binding specificity of their variable region; and thus, the resultant immunologic phenotype, which can often be specific to a person or to only a small percentage of people. Full definition →
Etymology from Wiktionary, CC BY-SA 4.0.