A classification of blood that is based on the presence or absence of antigens in the red blood cells of an individual. For the purposes of blood transfusion three antigens referred to as "A", "B" and "RhD" (out of a total of 29) are the most important. Based on their presence the human blood can be classified to A, AB, B, and O blood types which are further divided to Rh positive or negative
Someone's blood type is the same as their blood group. one of the classes into which human blood can be separated, including A, B, AB, and O British Equivalent: blood group