blood group

BLOOD GROUP = [biology] one of the different types of blood by which groups of people are identified COMMENT: Blood is classified in various ways. The most common classifications are by the agglutinogens in red blood corpuscles (factors A and B) and by the Rhesus factor. Blood can therefore have either factor (Group A or Group B) or both factors (Group AB) or neither (Group O) and each of these groups can be Rhesus negative or positive..