- another name for blood group
- The specific reaction pattern of red blood cells of an individual to the antisera of one blood group as, for example, of the ABO blood group, which consists of four major blood types, O, A, B, and AB.
- Blood group.
- Any of the four main types into which human blood is divided: A, B, AB, and O. Blood types are based on the presence or absence of specific antigens on red blood cells. Also called blood group